Bowen, Cathereve Drinker
Buku Teks
Farrington, B.
Henry Schuman, 1949
Buku Teks
Robert Maynard Hutchins, editor in chief
Encyclopaedia Britannica, Inc., 1952
Buku Referensi
Vickers, Brian
at the University Press, 1968
Buku Teks
Haas, Francis J.
Buku Teks