May, Larry, author
Cambridge University Press, 2019
eBooks
Sinnigen, William G.
Macmillan, 1981
Buku Teks
Han, Sang-nam
Sam Suy Chulpan sa, 2002
Buku Teks
Seagle, William
Hafner Publising Copmpany, 1971
Buku Teks
Cottrell, Leonard, author
Pan Books , 1977
Buku Teks