Wright, W., author
University Press, 1951
Buku Teks
Suarr, Richard W.
Brown and Benchmark, 1996
Buku Teks
Allen, Harry E.
Macmillan Publishing Company, 1989
Buku Teks
Suarr, Richard W.
Brown and Benchmark, 1996
Buku Teks
Kapliwatzky, Jochanan, author
Rubin Mass, 1954
Buku Referensi