Kim, Jong Il, author
Foreign Languages Pub. House, 2012
Buku Teks
Robert M. Hutchins, Mortimer J. Adler, editors in chief
Encyclopaedia Britannica, Inc., 1963
Buku Referensi
Robert M. Hutchins, Mortimer J. Adler, editors in chief
Encyclopaedia Britannica, Inc., 1963
Buku Referensi
ed. by Saxe Commins & Robert N. Linscott.
Random House , 1947
Buku Teks
Schlivek, Louis B., author
Doubleday, 1965
Buku Teks