Frisby, David
Routledge, 1992
Buku Teks
Appleton-Century-Crofts , 1967
Buku Teks
Giddens, Anthony
W.W. Norton & Compan, 2005
Buku Teks
Tischler, Henry L.
Wadsworth and Cengage Learning, 2014
Buku Teks
Mckee, James B.
Holt, Rinehart and Winston, 1969
Buku Teks