Howard, Darlene V.
Macmillan, 1983
Buku Teks
Shientag, Bernard L.
The Viking Press, 1943
Buku Teks
Runes, Dagobert D.
Philosophical Library, 1959
Buku Referensi
Carroll, John B.
Prentice-Hall, 1964
Buku Teks
Barnard, Alan
Cambridge University Press, 2012
Buku Teks