by Robert W. Parry ... [and others]
Prentice-Hall, 1970
Buku Teks SO
Clark, William R.
John Wiley & Sons, [Date of publication not identified]
Buku Teks SO
Clark, William R
John Wiley & Sons, 1991
Buku Teks SO
Campbell, Donald T.
Rand Mc Nally College Publisher, 1966
Buku Teks
Churchill, Gilbert A.
The Dryden Press, 1995
Buku Teks SO