O'Brien, P. G. (1993). Herbert Hoover: A bibliography (1. publ.). Greenwood Press.
Chicago Style (17th ed.) CitationO'Brien, Patrick G. Herbert Hoover: A Bibliography. 1. publ. Westport, Conn. u.a: Greenwood Press, 1993.
MLA (9th ed.) CitationO'Brien, Patrick G. Herbert Hoover: A Bibliography. 1. publ. Greenwood Press, 1993.
Warning: These citations may not always be 100% accurate.