Skoisen, K. Fred
South-Western Piblishing , 1983
Buku Teks
Buckley, John W., 1934-, author
John Wiley & Sons, 1980
Buku Teks
Carey, John L., author
Houghton Mifflin, 1977
Buku Teks
Wagner, Susan
Praeger Publishers, 1971
Buku Teks
Chatov, Robert
Free Press, 1975
Buku Teks