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
Ellis, Donald
Lawrence Erlbaum Asssociates, Publish., 1999
Buku Teks
Marden, Charles Frederick.
American Book Co, 1968
Buku Teks