Murphy, Robert F., author
Prentice-Hall, 1986
Buku Teks
Hammond, Peter, author
Macmillan, 1978
Buku Teks
Haviland, William A., author
Rinehart and Winston, 1975
Buku Teks
Lenkeit, Roberta Edwards, author
McGraw-Hill, 2012
Buku Teks
Rapport, Nigel, author
Routledge, 2000
Buku Teks