Whether confirmation hearings (a procedure unique to the Senate), legislative, oversight, investigative, or a combination of these, all hearings share common elements of preparation and conduct. Hearings usually include oral testimony from witnesses and questioning of the witnesses by members of Congress. George B. Galloway termed congressional hearings a goldmine of information for all the public problems of the United States. A leading authority on U.S. government publications has referred to the published hearings as "the most important publications originating within Congress." The Senate Library in a similar vein noted "Hearings are among the most important publications originating in Congress."