Newman, Edward I.
BlackWell Science , 2000
Buku Teks
Henry W. Art, general editor ; foreword by F. Herbert Bormann ; contributing editors, Daniel Botkin [and others]
Henry Holt, 1993
Buku Referensi
Veeresh, G.K.
Oxford & IBH Publishing Co., 1988
Buku Teks
Yayasan Obor Indonesia, 1988
Buku Teks
Butzer, Karl W.
Cambridge University Press, 1982
Buku Teks