Runes, Dagobert D., author
Paterson, 1963
Buku Teks
Mayer, Frederick, author
American Book Company, 1951
Buku Teks
Guthrie, W.K.C., author
Cambridge University Press, 1989
Buku Teks
Stumpf, Samuel Enoch, 1918-1998, author
McGraw-Hill, 1989
Buku Teks
Windelband, Wilhelm, author
Dover, 1956
Buku Teks