user3456: I have recently learned that former chess world champion Tigran Petrosian earned a PhD title from Yerevan State University; the title of his dissertation title was Chess Logic.
I would like to read what he wrote. I can read Russian. Any idea how to get hold of this text?
EDIT: I have just read in a chess history book that between his two matches with Spassky, Petrosian worked on the philosophy of the chess battle, studied the secrets of the process of chess thinking, successfully defended a dissertation on this subject and became a candidate of philosophical sciences - my translation from Russian. This cryptic text does not mention the title of doctor (PhD) but an obscure title of candidate.

user8453: There seems to be an English copy of a 39-page “personal summary by the author" (presumably not the full dissertation) here.

user10867: According to WorldCat.org, Tigran Petrosian's PhD thesis is available in three libraries: the Koninklijke Bibliotheek ("royal library") in The Hague (Netherlands), the Danish Union Catalogue and Danish National Bibliography (a catalogue strangely identified as a "library"?) and the State and University Library in Denmark. 
Apparently, the English translation is (or was) only available in 250 copies, so there may be other libraries that have it but that aren't covered by WorldCat.org. Once you've identified a library that has it, you can try to get a copy through interlibrary loan. (This may work best if you have access to a university library, especially for international interlibrary loan.) The other option is trying to buy it through a website for second-hand books, but the book is so rare that your chances of finding it are very small. 
See: 

Tigran Vartani Petrosjan: Chess Logic. Skakhus-forlaget, 1968. Translated from the Russian into English by Carl Andersen. (See the catalogue entry at the Koninklijke Bibliotheek.)
Tigran Vartani Petrosjan: Skak logik. Copenhagen : Skakhus, 1968. Translated into Danish by Carl Andersen. (See the catalogue entry at the Koninklijke Bibliotheek.)


user5756: There is another copy of the English edition in the University Library in Frankfurt am Main (Germany), here. 
This particular library obtained the chess book collection of Willi Summ (1896–1982) as donation in 1975. Though it is not as large as Cleveland or Den Haag, it possesses some rare volumes. The paper in question is no. 1379 in the printed catalogue:
@BOOK{summ:meissenburg:1982,
    EDITOR = {Summ, Willi AND Meissenburg, Egbert},
    TITLE = {Der Frankfurter Schachbücherkatalog},
    SUBTITLE = {Schachschriften in der Stadt- und Universitätsbibliothek Frankfurt am Main},
    DATE = {1982},
    PAGETOTAL = 116,
    PUBLISHER = {Schachverlag Horst Helten},
    LANGUAGE = {german},
    GENDER = {pm},
    EDITORTYPE = {compiler},
    ISBN = {3-922853-03-X},
    EDITION = 2,
}


3456: <p>I have recently learned that former chess world champion Tigran Petrosian earned a PhD title from Yerevan State University; the title of his dissertation title was <em>Chess Logic</em>.</p>

<p>I would like to read what he wrote. I can read Russian. Any idea how to get hold of this text?</p>

<p>EDIT: I have just read in a chess history book that between his two matches with Spassky, Petrosian worked on the philosophy of the chess battle, studied the secrets of the process of chess thinking, successfully defended a dissertation on this subject and became a candidate of philosophical sciences - my translation from Russian. This cryptic text does not mention the title of doctor (PhD) but an obscure title of candidate.</p>
 8453: <p>There seems to be an English copy of a 39-page “personal summary by the author" (presumably not the full dissertation) <a href="http://chessdevon.co.uk/HTML/Book%20sale/instructional.htm" rel="nofollow">here</a>.</p>
 10867: <p>According to <strong>WorldCat.org</strong>, Tigran Petrosian's PhD thesis is available in three libraries: the Koninklijke Bibliotheek ("royal library") in The Hague (Netherlands), the Danish Union Catalogue and Danish National Bibliography (a catalogue strangely identified as a "library"?) and the State and University Library in Denmark. </p>

<p>Apparently, the English translation is (or was) only available in 250 copies, so there may be other libraries that have it but that aren't covered by WorldCat.org. Once you've identified a library that has it, you can try to get a copy through <strong>interlibrary loan</strong>. (This may work best if you have access to a university library, especially for international interlibrary loan.) The other option is trying to buy it through a website for second-hand books, but the book is so rare that your chances of finding it are very small. </p>

<p>See: </p>

<ol>
<li>Tigran Vartani Petrosjan: <a href="http://www.worldcat.org/title/chess-logic/oclc/486152222?referer=br&amp;ht=edition" rel="nofollow noreferrer"><em>Chess Logic</em>. Skakhus-forlaget, 1968</a>. Translated from the Russian into English by Carl Andersen. (See the <a href="http://opc4.kb.nl/DB=1/XMLPRS=Y/PPN?PPN=123164818" rel="nofollow noreferrer">catalogue entry at the Koninklijke Bibliotheek</a>.)</li>
<li>Tigran Vartani Petrosjan: <a href="http://www.worldcat.org/title/chess-logic/oclc/69386187?referer=br&amp;ht=edition" rel="nofollow noreferrer"><em>Skak logik</em></a>. Copenhagen : Skakhus, 1968. Translated into Danish by Carl Andersen. (See the <a href="http://opc4.kb.nl/DB=1/XMLPRS=Y/PPN?PPN=123164923" rel="nofollow noreferrer">catalogue entry at the Koninklijke Bibliotheek</a>.)</li>
</ol>
 5756: <p>There is another copy of the English edition in the University Library in Frankfurt am Main (Germany), <a href="http://kvk.bibliothek.kit.edu/view-title/index.php?katalog=HEBIS_RETRO&amp;url=http%3A%2F%2Forsprod.rz.uni-frankfurt.de%2FDB%3D1.50%2FCHARSET%3DUTF-8%2FIMPLAND%3DY%2FLNG%3DDU%2FSRT%3DYOP%2FTTL%3D1%2FCOOKIE%3DU203%2CK203%2CI251%2CB1999%2B%2B%2B%2B%2B%2B%2CSN%2CNDefault%2Blogin%2CD1.50%2CE11542a73-1%2CA%2CH%2CR129.13.130.211%2CFY%2FSET%3D1%2FSHW%3FFRST%3D1&amp;signature=zyusH_ldMaZ0hn4i-jGOuqOLR4NRlENAjncBk8q7WnI&amp;showCoverImg=1" rel="nofollow noreferrer">here</a>. </p>

<p>This particular library obtained the chess book collection of Willi Summ (1896–1982) as donation in 1975. Though it is not as large as Cleveland or Den Haag, it possesses some rare volumes. The paper in question is no. 1379 in the printed catalogue:</p>

<pre><code>@BOOK{summ:meissenburg:1982,
    EDITOR = {Summ, Willi AND Meissenburg, Egbert},
    TITLE = {Der Frankfurter Schachbücherkatalog},
    SUBTITLE = {Schachschriften in der Stadt- und Universitätsbibliothek Frankfurt am Main},
    DATE = {1982},
    PAGETOTAL = 116,
    PUBLISHER = {Schachverlag Horst Helten},
    LANGUAGE = {german},
    GENDER = {pm},
    EDITORTYPE = {compiler},
    ISBN = {3-922853-03-X},
    EDITION = 2,
}
</code></pre>
