Schaefer, Richard T, author
McGraw-Hill, 2009
Buku Teks
Giddens, Anthony, author
W.W. Norton & Compan, 2005
Buku Teks
Tischler, Henry L.
Wadsworth and Cengage Learning, 2014
Buku Teks
Mckee, James B., author
Holt, Rinehart and Winston, 1969
Buku Teks
Gillin, John Lewis, author
Macmillan, 1942
Buku Teks