David Vlahov
Jossey-Bass, 2010
Buku Teks
Hardy, Margaret E.
Appleton-century-crofts , 1978
Buku Teks SO
edited by D.R. Rutter, and Lyn Quine
Avebury, 1994
Buku Teks SO
James A. Johnson, Carleen H. Stoskopf
Jones and Bartlett Publishers, 2010
Buku Teks
Malcolm Maclachlan
John Wiley & sons Ltd, 2000
Buku Teks SO