Henry W. Art, general editor ; foreword by F. Herbert Bormann ; contributing editors, Daniel Botkin [and others]
Henry Holt, 1993
Buku Referensi
Porteous, Andrew, author
John Wiley & Sons, 1992
Buku Referensi
McGraw-Hill, 2003
Buku Referensi
Brewer, Richard, author
Saunders College Publishing, 1994
Buku Teks
Ehrlich, Paul R., author
Macmillan, 1987
Buku Teks