Robert H. Binstock, Linda K. George, editor
Elsevier , 2011
Buku Teks
Harcourt, Brace & World, 1970
Buku Teks
Webster, Murray, editor
Academic Press, 2014
eBooks
Stebbins, Robert A., author
Sage, 2001
Buku Teks
edited, Bridget Somekh, Cathy Lewin
Sage Publications , 2005
Buku Teks