1951
Buku Teks
editor, Frederick G. Ruffner, Robert C. Thomas, Ann Underwood, Harold C. Young
Gale Research, 1964
Buku Referensi
Grolier Incorporated, 1964
Buku Referensi
Mower, Alfred Glenn, author
Connecticut Greenwood Press 1979,
Buku Referensi
Mower, Alfred Glenn, author
Greenwood Press, 1979
Buku Teks