Huttermann, Michael, author
Oxford University Press, 2017
eBooks
Conn, Steven, author
University of Pennsylvania Press, 2003
Buku Teks
edited by Karl W. Deutsch and William J. Foltz
Atherton Press, 1966
Buku Teks
Hardgrave, Robert L., author
Harcourt, Brace, 1970
Buku Teks
Hardgrave, Robert L., author
Harcourt College, 2000
Buku Teks