Spulber, Nicolas
Indiana University Press, 1971
Buku Teks
Kim, Il Sung, author
Foreign Languages Publishing House, 1958
Buku Teks
Shannon, David A.
Macmillan, 1995
Buku Teks
Csikos-Nagy, Bela, author
Akademiai Kiado, 1975
Buku Teks
Berger, P.
Buchdruckerei Gasser and Cie, 1977
Buku Teks