Gray, Ivan
Learning matters Ltd., 2010
Buku Teks
Southern Public Adminitration Education Foundation Inc, 2018
Majalah, Jurnal, Buletin
edited by Saul Feldman
Charles C. Thomas, 1980
Buku Teks SO
Reynolds, Amanda
Open universtity press , 2000
Buku Teks SO
edited by Anthony R. Kovner and Duncan Neuhauser
Health Administration Press, 1983
Buku Teks