Search by Author for books by a particular author. For private communications, memoirs, etc. An encyclopedia of data, key documents, biography, relationship to other gov't branches, the executive offices, powers, selection and removal, etc. An unannotated list of books and articles on all aspects of the office. An excellent guide to the sources of information for research about the presidency, including official documents, campaigning, election data, etc.
Survey responses to questions, many about the presidency and party politics.
An index to popular and news magazines, some with political commentary. Very useful for researching any public policy issues.