edited by Peter Bradley and Amanda Burls
Routledge, 2000
Buku Teks
edited by Robert D. Newcomb, Jerry L. Jolley
Charles C. Thomas, 1980
Buku Teks
Gray, Stephen E.
MacMillan Press , 1978
Buku Teks
Herman, Harold
International City Managers Association, 1968
Buku Teks
Smolensky, Jack
W B Saunders company, 1972
Buku Teks SO