Lieuwen, Edwin
Frederick A. Praeger, 1960
Buku Teks SO
Robin, Ranger
Gage, 1979
Buku Teks SO
Edward, David V.
Holt, Rinehart and Winston, 1969
Buku Teks SO
edited by R. James Woolsey
ICS Press, 1984
Buku Teks
Ray, James Lee
Houghton Mifflin, 1987
Buku Teks SO