Kinyon, Stanley V.
West Publishing Company, 1971
Buku Teks
Hegland, Kenney F., author
Thomson West, 2003
Buku Teks
Holsinger, Ralph L., author
McGraw-Hill, 1994
Buku Teks
Praegar, 1976
Buku Teks
Lawhorne, Clifton O., author
Southern Illinois University Press, 1971
Buku Teks