Doran, Bruce J.
Springer, 2012
eBooks
Sheley, Joseph F., author
Wadsworth, 1987
Buku Teks
Magnuson, Roger J., author
McGraw-Hill, 1992
Buku Teks
edited by Katja Franko Aas
Sage Published, 2013
Buku Teks
Baker, Thomas E., author
Pearson - Prentice Hall, 2005
Buku Teks