Langman, Larry, author
Garland Pub, 1990
Buku Referensi
Americana Corporation, 1980
Buku Referensi
Americana Corporation, 1980
Buku Referensi
editor, Gorton Carruth
Thomas Y. Growell, 1962
Buku Referensi
Paneth, Donald, author
Facts on File, 1983
Buku Referensi