Smith, J. W., author
New Worlds Express , 1989
Buku Teks
Brown, A.J., author
George Allen and Unwin, 1959
Buku Teks
Brown, A.J., author
George Allen and Unwin, 1959
Buku Klasik
Daughterty, Caroll R., author
Houghton Mifflin, 1950
Buku Teks
McKenzie, Richard B., author
McGraw-Hill, 1978
Buku Teks