LaPalombara, Joseph
Conference Board, 1977
Buku Teks SO
Shapiro, Alan C.
Prentice-Hall, 1998
Buku Teks
Shapiro, Alan C.
John Wiley & Sons, 2003
Buku Teks
Cullen, John Brooks, 1948-
Thomson, 2005
Buku Teks SO
Martyn, Howe
Lexington Books, 1972
Buku Teks