Christian Soe
McGraw-Hill, 2004
Buku Teks
Macridis, Roy C., author
Dorsey Press, 1972
Buku Teks
Denny J.A., author
Jayabaya University Press , 1999
Buku Teks SO
Brown, Bernard E. (Bernard Edward), author
Thomson, 2006
Buku Teks
edited by Roy C. Macridis and Bernard E. Brown
Wadsworth, 1990
Buku Teks