World Bank, 1974
Buku Teks
Montemayor, Jeremias U.
Rex Book Store, 1976
Buku Teks
edited by Gerard Caprio, Jr., Izak Atiyas, and James A. Hanson
Cambridge University Press, 1996
Buku Teks
Jocano, F. Landa
Philippine Center for Advanced Studies, 1975
Buku Teks
Dore, R.P.
Oxford University Press , 1959
Buku Teks