Sidheswar, N.
ata McGraw-Hill, 1980
Buku Teks
Frye, Richard N.
Henry Holt and Company, 1953
Buku Teks
Frye, Richard N.
Allen & Unwin , 1960
Buku Teks
Poirier, N.
Marcel Broquel, 1982
Buku Teks
W. Van Hoeve, [date of publication not identified]
Buku Referensi