Ateneo de Manila University Loyola Schools,
Majalah, Jurnal, Buletin
Ateneo de Manila University Loyola Schools, 2006, {s.a}
Majalah, Jurnal, Buletin
Office of Research and publications loyola schools,
Majalah, Jurnal, Buletin
Bartholomew, David J.
John Wiley & Sons, 1981
Buku Teks
Boulding, Kenneth E. (Kenneth Ewart), 1910-1993
Fefer and Simons , 1966
Buku Teks