Readings on color : volume 2, the science of color
edited by Alex Byrne, David R. Hilbert
MIT Press, 1997
 Buku Referensi
Rethinking the color line : readings in race and ethnicity
Charles A Gallagher, editor
McGraw-Hill, 2012
 Buku Teks
Entreves, A.P.D
Natural law an introduction to legal philosphy
Hutchinson of London, 1970
 Buku Teks
Lands and peoples : the world in color, volume 1 British Isles, Western Europe
Grolier Incorporated, 1964
 Buku Referensi
Santillana, Giorgio De
The age of adventure the renaissance philosphy/Giorgio De Santillana
A Mentor Book,
 Buku Teks