Solidaridad, 1969
Buku Teks
Ateneo De Manila University Press, 1976
Buku Teks
Manuel, A. Arsenio
Manila: Filipiniana Publications, 1948
Buku Teks
Ortiz, Alfonso
University of Chicago Press, 1969
Buku Teks
Marcos, Ferdinand E., author
Marcos Foundation , 1973
Buku Teks