opinion: HAYS, Circuit Judge:
  This is a diversity action in which plaintiff-appellee, the son of lyric writer Mack Gordon, seeks a declaratory judgment establishing him as a 50% owner of a % interest in the renewal copyright of the musical composition “Time On My Hands, You In My Arms.” “Time On My Hands” was composed by Vincent Youmans; Mack Gordon collaborated with Harold Adamson on the lyrics. A partial summary judgment was awarded to appellee on the ground that there was no valid and subsisting assignment from Mack Gordon to either of the appellants. Upon an express determination that there was no just reason for delay, the court expressly directed the entry of final judgment. Rule 54(b) of the Federal Rules of Civil Procedure.
  Appellee’s summary judgment motion was predicated upon documentary exhibits and the affidavits of his attorney. The Supreme Court has recently said: “On summary judgment the inferences to be drawn from the underlying facts contained in such materials must be viewed in the light most favorable to the party opposing the motion.” United States v. Diebold, Inc., 369 U.S. 654, 655, 82 S.Ct. 993, 994, 8 L.Ed.2d 176 (1962). With this admonition in mind, we find that the inferences to be drawn from the facts do not support the granting of summary judgment. We therefore reverse and remand for a trial of the issues.
  On August 12, 1930, Mack Gordon assigned to appellant, Vincent Youmans, Inc., all rights, including renewal copyrights, in any song that he might write. On March 11, 1931, two separate documents, a release between Gordon and Vincent Youmans, Inc. and an assignment by Gordon to appellant, Miller Music Corporation, of the rights to nineteen named songs were executed. “Time On My Hands” was not included in this latter group. On September 10, 1931, Vincent Youmans, Inc., purported to assign its rights in “Time On My Hands” to Miller Music Corporation.
  The August 12,1930 assignment reads:
  “The Lyric Writer agrees for himself, if living, and for his administrator, executors and next of kin, if not living, to renew, pursuant to law, the copyrights of each and all of the numbers delivered to the Publisher and copyrighted by the Publisher hereunder, and to assign such renewals of copyright to the Publisher for continued publication pursuant to the provision hereof.”
  “Time On My Hands” was included in the assignment.
  There is no dispute about the meaning or scope of the agreement of August 12, 1930. There is, however, a dispute as to its continued existence. Appellee properly asks why royalties were never paid and royalty statements never rendered to Mack Gordon as required by the agreement. He quotes Miller Music Corporation’s attorney as stating that the agreement was cancelled. On the other hand, appellants ask why Gordon never exhibited an interest in “Time On My Hands” or claimed the right to royalties.
  Appellants allege that Gordon executed a release, now missing, in which he renounced all rights to royalty payments for “Time On My Hands.” The affidavit of John F. Fitzgerald, controller of Miller Music Corporation, indicated that he had “found correspondence in the files * * referring to said document.” The status of the ease as we see it requires that the factual questions presented here be resolved in the district court after a full trial.
  Even more important in their bearing on the rights to “Time On My Hands” are the two agreements of March 11 and the agreement of September 10, 1931. New York law, which is applicable in this diversity action, requires that all writings that form part of a single transaction and are designed to effectuate the same purpose be read together, even though they were executed on different dates and were not all between the same parties. Kurz v. United States, 156 F.Supp. 99, 103-104 (S.D.N.Y.1957), aff'd per curiam, 254 F.2d 811, 812 (2d Cir. 1958); Nau v. Vulcan Rail & Construction Co., 286 N.Y. 188, 36 N.E.2d 106 (1941).
  In Kurz, where the District Court held that the law of New York was to be applied, the documents read together were a “Separation Agreement,” between decedent and his wife, dated October 16, 1931 and a “Trust Instrument,” between decedent and his trustee, dated December 4, 1931. This Court observed, in affirming per curiam, “it is both good sense and good law that these closely integrated and nearly contemporaneous documents be construed together.” Kurz v. United States, 254 F.2d 811, 812 (2d Cir. 1958). In Nau three agreements were read together in order to determine whether the defendant was liable for expenses incurred by plaintiff in defending a patent interference proceeding. The court concluded that the three agreements “were executed at substantially the same time, related to the same subject-matter, were contemporaneous writings and must be read together as one.” Nau v. Vulcan Rail & Construction Co., 286 N.Y. 188, 197, 36 N.E.2d 106, 110 (1941); see In re Herzog, 301 N.Y. 127, 135-136, 93 N.E.2d 336, 339 (1950); Knowles v. Toone, 96 N.Y. 534, 536 (1884); Restatement of Contracts § 235(c); 4 Williston, Contracts § 628 at 904 (3d ed. 1961); cf. Marsh v. Dodge, 66 N.Y. 533, 537-538 (1876).
  The language of the March 11,1931 release is broad, but when taken in the context of all three agreements its meaning is not clear. Vincent Youmans, Inc., released Mack Gordon “from all manner of action and actions * * * covenants, contracts * * * from the beginning of the world to the day of the date of these presents.” The release was predicated upon a payment of consideration, “lawful money * * * to [Youmans, Inc.,] * * * by Mack Gordon.” However, the assignment, also signed on March 11, between Gordon and Miller Music Corporation recited:
  “the Authors were heretofore under contract to Vincent Youmans,. Inc. in respect to the foregoing musical numbers listed in ‘Schedule A’, from which contracts the Publisher had obtained releases for the Authors by the payment of substantial consideration * * * The procurement of such release by the Publisher together with the provision for the payment of royalties to the Authors hereunder and the other agreements on the part of the parties hereto constitute the consideration of this agreement.”
  No particular form of words is required to make a written release effective; all that is necessary is that the words show an intention to discharge. The scope and meaning of a release will be determined by the manifested intent of the parties — in Corbin’s words, “by the process of interpretation, just as in the case of determining the meaning of an executory contract.” 5A Corbin, Contracts § 1238 at 560 (1964).
  Here, the recital in the contemporaneous assignment casts doubt upon the purpose and meaning of the release. See Television Credit Corp. v. International Television Corp., 279 App.Div. 561, 107 N.Y.S.2d 179, 180 (1951). The release expressly calls for a payment from Gordon to Youmans; the assignment makes clear that Miller Music Corporation, not Gordon, was to supply the consideration for the release. “Time On My Hands” was not included in Schedule A of the assignment. Why should Miller Music Corporation pay for the release of a composition the rights to which it was not receiving? It seems not unlikely that the assignment indicates that the broad language of the release was mere boiler plate. One might reasonably conclude that the parties intended to limit the release to the compositions listed on Schedule A.
  On September 10, 1931 Vincent You-mans, Inc., assigned the copyright interest that it obviously assumed it had in “Time On My Hands” to Miller Music Corporation. Clearly, then, neither Vincent Youmans, Inc., the granting party in the March 11 release, nor Miller Music Corporation, the third party supplying the consideration for the release, intended or believed that the release was all-encompassing.
  Where ambiguity is present in a contract, the subsequent conduct of the parties may be used to indicate their intent. See Town of Pelham v. City of Mount Vernon, 304 N.Y. 15, 23, 105 N.E. 2d 604, 608 (1952); Seymour v. Warren, 179 N.Y. 1, 6, 71 N.E. 260, 261 (1904) (“There is no better way of ascertaining the meaning and construction of a written contract than to look at the acts and conduct of the parties under it.”); 1 Corbin, Contracts § 101 (1964). From September 10, 1931 until his death in February 1959, Mack Gordon never exhibited any interest in what appellee now alleges was his undisputed property. Certainly, from his conduct, an inference may be drawn that Gordon believed that the release was limited to the songs in Schedule A, and that the Youmans’ assignment of September 10 was, therefore, effective.
  We believe that these doubts as to the meaning of the release and the two assignments preclude summary judgment. The three agreements present a confusing picture. The case must be remanded for a trial of the facts in order to resolve the doubts. There is no other way to establish the true intent of the parties.
  Mack Gordon died in February 1959, almost four months after the copyright renewal term began and more than fifteen months after the beginning of the period during which the right to renewal was in effect. (The copyright may be renewed “within one year prior to the expiration of the original term of copyright.” 17 U.S.C. § 24.) Appellee’s rights were not distributed by the executor until February 15, 1963; this action was not instituted until August 5,1963. Thirty-two years elapsed before the appellants’ rights were challenged. During the intervening period Vincent Youmans and others with first-hand knowledge of the transaction died; documents that might have been helpful were lost. The rights under the original and renewal copyrights stem from the same source, and claims under one are inextricably tied to the other. The appellants may have been prejudiced by the delay. The fact that appellee has sued only on the renewal copyright does not preclude a finding of laches. Though we do not intend by this discussion to intimate any opinion on the subject, the district court on remand may find it necessary to consider the issue.
  Reversed and remanded.
  . Appellee also demanded an accounting for royalties received by Miller Music Corporation on the renewal copyright.
  . See, e.g., the discussion of the missing release, supra.
instruction: What follows is an opinion from a United States Court of Appeals.
  Intervenors who participated as parties at the courts of appeals should be counted as either appellants or respondents when it can be determined whose position they supported. For example, if there were two plaintiffs who lost in district court, appealed, and were joined by four intervenors who also asked the court of appeals to reverse the district court, the number of appellants should be coded as six.
  When coding the detailed nature of participants, use your personal knowledge about the participants, if you are completely confident of the accuracy of your knowledge, even if the specific information is not in the opinion. For example, if "IBM" is listed as the appellant it could be classified as "clearly national or international in scope" even if the opinion did not indicate the scope of the business. 
  
  Your task concerns the first listed appellant. The nature of this litigant falls into the category "private business (including criminal enterprises)", specifically "other". Your task is to determine what subcategory of business best describes this litigant.
choices: medical clinics, health organizations, nursing homes, medical doctors, medical labs, or other private health care facilities private attorney or law firm media - including magazines, newspapers, radio & TV stations and networks, cable TV, news organizations school - for profit private educational enterprise (including business and trade schools) housing, car, or durable goods rental or lease entertainment: amusement parks, race tracks, for profit camps, record companies, movie theaters and producers, ski resorts, hotels, restaurants, etc. information processing consulting security and/or maintenance service other service (including accounting) other (including a business pension fund) unclear