Spitzer, R. J. (2012). The presidency and public policy: The four arenas of presidential power (Paperback ed.). University of Alabama Press.
Lua i Stíl Chicago (17ú heag.)Spitzer, Robert J. The Presidency and Public Policy: The Four Arenas of Presidential Power. Paperback ed. Tuscaloosa: University of Alabama Press, 2012.
Lua MLA (9ú heag.)Spitzer, Robert J. The Presidency and Public Policy: The Four Arenas of Presidential Power. Paperback ed. University of Alabama Press, 2012.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.