Mortimer J. Adler, editor in chief
Encyclopedia Britanica, 1994
Buku Referensi
Robert Maynard Hutchins, editor in chief
Encyclopaedia Britannica, Inc., 1952
Buku Referensi
Artikel Jurnal
edited by Harold C. Gardiner
Devin-Adair Co., 1949
Buku Teks
Tucker, Caroline, author
Ariel & Books, 1962
Buku Teks