Hurd, Geoffrey
Routledge , 1973
Buku Teks
Bell, Earl H.
Harper & Row, 1965
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