Neuman, William Lawrence, 1950-, author
Allyn and Bacon, 2000
Buku Teks
Creswell, John W., author
Sage, 2014
Buku Teks
Frost, Nollaig, author
McGraw-Hill, 2011
Buku Teks
edited by Jonathan A. Smith
SAGE, 2015
Buku Teks
Lawrence R. Frey...[et al.]
Prentice-Hall, 1991
Buku Teks