Ashford, Jose B, author
Thomson Brooks, 2006
Buku Teks
Anderson, Ralph E., author
Aldine, 1974
Buku Teks
Carter, Irl, author
AldineTransaction, 2011
Buku Teks
Wormer, Katherine Stuart van, author
Oxford University Press, 2017
Buku Teks
Canter, David
Buku Teks