Stephen J. Wayne [et all.]
Thomson, 2005
Buku Teks SO
Edward, David V.
Prentice-Hall, 1982
Buku Teks SO
Handlin, David p
Thames And Hudson, 1985
Buku Teks SO
Office of International Information Programs, 1991
Buku Teks SO
Patrick, John
Macmillan Publishing Company, 1984
Buku Teks SO