Dickenson pub, 1969
Buku Teks
Carroll, John B.
Harvad University Press, 1953
Buku Referensi
Mann, Arthur
Gadjah Mada University Press, 1990
Buku Teks
Peters, Thomas J.
Sang saka gotra, 1985
Buku Teks
Gibson, Charles, author
Harper & Row, 1966
Buku Teks