Lovejoy, Wallace F.
The John Hopkins Press , 1967
Buku Teks
Garfield, Paul J.
Prentice-Hall, 1964
Buku Teks
Homan, Paul T.
Harcourt, Brace and Company, 1958
Buku Teks
Einzig, Paul
Eyre & Spottiswood , 1949
Buku Teks
Beckmann, Poul, author
McGraw-Hill, 1995
Buku Teks