Lachica, Eduardo
Solidaridad Publishing House, 1971
Buku Teks
Davis, William G.
University of California Press, 1973
Buku Teks
Timberman, David G.
M.E. Sharpe, 1991
Buku Teks
Vicente C. Reyes, Jr
2002
Artikel Jurnal
Jocano, F. Landa
Philippine Center for Advanced Studies, 1975
Buku Teks