Hitch, Charles J.
University of California Press, 1965
Buku Teks
Van de Ven, Andrew H.
Kent State University Press, 1974
Buku Teks
Hernon, Peter
Ablex, 1990
Buku Teks
Fishburn, Peter C.
John Wiley & Sons, 1970
Buku Teks
edited by Maureen D. Raynor, Jayne E. Marshall and Amanda Sullivan
Elsevier, 2005
Buku Teks