Grolier, 1994
Buku Referensi
Warren Thomas Reich, editor in chief
Simon & Schuster Macmillan, 1995
Buku Referensi
Edgar F. Borgatta, editor-in-chief, Marie L. Borgatta, managing editor
Macmillan, 1992
Buku Referensi
edited by Alan Bryaman
Sage, 2001
Buku Referensi
R. R. Bowker Company, 1967
Buku Referensi