Malchow, Howard L., author
Bloomsbury Academic, an imprint of Bloomsbury Pub, 2016
Buku Teks
Williams, Phil, author
Thomson Wadsworth, 2006
Buku Teks
Magruder, Frank Abbott
Allyn and Bacon, 1939
Buku Teks
Pearson, Frederic S., author
McGraw-Hill, 1992
Buku Teks
edited by John Baylis and Steve Smith
Oxford University Press, 2006
Buku Teks