James, Preston E., author
John Wiley & Sons, 1980
Buku Teks SO
Israel, Saul, author
Holt, Rinehart and Winston, 1976
Buku Teks
Kolevzon, Edward R., author
Allyn and Bacon, 1959
Buku Teks
by Christopher L. Salter ... [et al.]
Saunders College Publishing, 2000
Buku Teks
James, Preston E., author
Macmillan, 1972
Buku Teks SO