Amyot, Jacques
John Murray, 1939
Buku Teks
Manila : Bureau of National and Foreign Infermation
Majalah, Jurnal, Buletin
Francisco, Juan R., author
Linguistic Society of The Philippines, 1973
Buku Teks
Forbes, W. Cameron
Houghton Mifflin, 1928
Buku Teks
Reyess, Elizabeth, author
Tuttle Publishing, 2012.
Buku Teks