Gray, Paul E.
Wiley Eastern, 1969
Buku Teks
Gates, Earl D., 1945-
Delmar Cengage Learning, 2012
Buku Teks
Romanowitz, H. Alex
John Wiley & Sons, 1968
Buku Teks
D. Jennings ... [et al.]
Edward Arnold, 1995
Buku Teks
Hart, Daniel W.
Prentice Hall International, 1997
Buku Teks