Peter Suwarno
Gadjah Mada University Press, 1999
Buku Referensi
Flavell, Roger
Kyle Cathie, 1995
Buku Referensi
Dando, Sylvia
McGraw-Hill Book, 1987
Buku Referensi
Shipley, Joseph T.
Philosophical Library, 1945
Buku Referensi
Maclagan, Thomas T.
Thomas Nelson and Son, 1929
Buku Referensi