Lawrence R. Frey...[et al.]
Prentice-Hall, 1991
Buku Teks
Wiersma, William, author
Pearson/Allyn and Bacon, 2005
Buku Teks
Wiersma, William, author
Pearson, 2009
Buku Teks
Zechmeister, Eugene B., author
McGraw-Hill, 1992
Buku Teks
Basil Gomez and John Paul Jones III, edited
Wiley-Blackwell, 2010
Buku Teks SO