C.A. Qadar
Pakistan Philosophical Congress, 1965
Buku Teks
Markus, John, 1911-, author
McGraw-Hill, 1974
Buku Referensi
McCullagh, C. Behan, author
Routledge, 1998
Buku Teks
Armstrong, D. M., author
Cambridge University Press, 2004
Buku Teks
Greenstein, Carol Horn, author
Van Nostrand Reinhold, 1978
Buku Referensi