The Encyclopedia Americana : volume 3
Grolier, 1994
 Buku Referensi
Encyclopedia of bioethics : volume 3
Warren Thomas Reich, editor in chief
Simon & Schuster Macmillan, 1995
 Buku Referensi
Encyclopedia of sociology; Volume 3
edited by Edgar F. Borgatta, Marie L. Borgatta
Macmillan, 1992
 Buku Referensi
Grolier academic encyclopedia 3
London: Grolier International, 1991,
 Buku Referensi
Encyclopedia of mathematics Vol. 3
Kluwer Academic Publishers, 1995,
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