Mortimer J. Adler, editor in chief
Encyclopedia Britanica, 1994
Buku Referensi
editor in chief, Mortimer J. Adler
Encyclopedia Britanica,
Buku Referensi
Artikel Jurnal
edited by Harold C. Gardiner
Devin-Adair Co., 1949
Buku Teks
editor in chief, Mortimer J. Adler
Encyclopedia Britanica, 1990
Buku Referensi