Sherry, John C.
Collier Books, 1963
Buku Teks SO
Harrison, John B.
Alfred A. Knopf, 1969
Buku Teks SO
Harrison, John B.
Alfred A. Knopf, 1966
Buku Teks SO
edited by S.J. De Leat, A.H. Dani, J.L. Lorenzo and R.B. Nunoo
Routledge , 1994
Buku Referensi
Campbell, Kenneth L., 1955-
Bloomsbury, 2015
Buku Teks SO