Steinberg, David J. (David Joel), author
Westeriew Press, 1990
Buku Teks
Romero, Flerida Ruth P., author
U.P. Law Center, 1981
Buku Teks
Saniel, Josefa M., author
University of the Philippines, 1963
Buku Teks
Corpuz, Onofre D.
Prentice-Hall, 1965
Buku Teks
Nelson, Raymond
Thames and Hudson, 1968
Buku Teks