Forbes, Cameron W.
Houghton Miffiln, 1928
Buku Klasik
Abaya, Hernando J., author
Malaya BOoks, 1970
Buku Teks
Marcos, Ferdinand E., author
Marcos Foundation, 1974
Buku Teks
Hayder, Joseph Ralston
Macmillan, 1950
Buku Teks
Spence, Hartzell
The World Publishers, 1969
Buku Teks