Prytherch, Ray, compiler
Gower, 2000
Buku Referensi
Chandos , 2013
eBooks
Dorland, W. A. Newman
W.B. Saunders Company , 1994
Buku Referensi
Katz, William A., 1924-, author
Holt, Rinehart and Winston, 1979
Buku Teks
Cook, Margaret G., author
The H.W. Wilson Company, 1963
Buku Teks