Agoncillo, Teodora A.
A Mentor Book, 1969
Buku Teks
Hein, Fred V.
Chicago Scott Foresman , 1965
Buku Teks
Sydenstricker, Edgar
PRODIST, 1974
Buku Teks
Ramanadham, V.V.
Asia Publishing House, 1963
Buku Teks
Veninga, Robert L.
Prentice Hall Inc., 1982
Buku Teks