Krantz, John C., author
Williams & Wilkins, 1974
Buku Teks
Smith, Mickey A., author
The Williams and Wilkins, 1976
Buku Teks
Charles W. Eliot, edited
P. F. Collier & Son Corporation, 1959 ; 1969
Buku Referensi
eited by Charles W. Eliot
Grolier Enterprises Corp., 1995
Buku Referensi
Information Canada, 1972
Buku Teks