Groenewegen, Peter Diderik, author
George Allen and Unwin, 1985
Buku Teks
Buku Teks
by R.I. Downing ... [and others]
Melbourne University Press , 1964
Buku Teks
Lehmann, Geoffrey, author
LBC Information Service, 1996
Buku Teks
Gribbin, John, author
Yale University Press, 1999
Buku Referensi