Manuel, A. Arsenio
Manila: Filipiniana Publications, 1948
Buku Teks
Vendryes, J. (Joseph), 1875-1960
Routledge, 1996
Buku Teks
Sturtevant, Edgar H.
Yale University Press, 1947
Buku Teks
Pike, Kenneth L. (Kenneth Lee), 1912-2000
University of Nebraska Press, 1982
Buku Teks
Victoria A. Fromkin
Blackwell Publishers, 2001
Buku Teks