Prabhu, Anjali
Wiley Blackwell, 2014
Buku Teks SO
edited by I. William Zartman and William Mark Habeeb
Westerview Press, 1993
Buku Teks SO
Murdock, George Peter
McGraw-Hill, 1959
Buku Teks
Murdock, George Peter
McGraw-Hill, 1959
Buku Teks
edited by Phillis M. Martin and Patrick O'Meara
Indiana University Press, 1995
Buku Teks SO