Cowell, F. R.
Adam and Charles Black, 1952
Buku Teks
Stanford, Michael
Blackwell Publishers, 1998
Buku Teks
Hegel,G.W.F
The Boss-Merrill Company, INC, 1953
Buku Teks
Dray, William H.
Prentice-Hall, 1993
Buku Teks
Stumpf, Samuel Enoch, 1918-1998, author
McGraw-Hill, 2012
Buku Teks