Marczyk, Geoffrey, author
John Wiley & Sons, 2005
Buku Teks
Kumar, Ranjit, author
SAGE, 2014
Buku Teks
Gomm, Roger, author
Palgrave McMillan, 2004
Buku Teks
Paul M. Camic, Jean E. Rhodes, Lucy Yardley
APA, 2007
Buku Teks
Neuman, William Lawrence, 1950-, author
Allyn and Bacon, 2000
Buku Teks