McNeill, Patrick
Routledge, 1990
Buku Teks
White, Theresa L.
Wadsworth and Cengage Learning, 2013
Buku Teks
McNeill, Patrick
Routledge, 1999
Buku Teks
edited by Bryant W. Rossiter, John F. Hamilton
John Wiley & Sons, 1990
Buku Teks
Drago, Russell S.
Saunders College, 1992
Buku Teks