Fuller, Graham E.
Westeriew Press, 1991
Buku Teks SO
Hope, Michael
Oxford University Press, 2016
eBooks
Frye, Richard N.
Henry Holt, 1953
Buku Teks SO
Frye, Richard N.
George Allen & Unwin, 1960
Buku Teks SO
Shannon, William V.
Macmillan, 1967
Buku Teks SO