Freeman, John M.
The Johns Hopkins University Press , 1997
Buku Teks
Berbar, Halim, author
Times Editions-Marshall Cavendish, 2004
Buku Referensi
Frank, Patricia, author
Wiley, 2011
eBooks
Gribbin, John, author
Yale University Press, 1999
Buku Referensi
edited by Ronald P. Grelsamer and Suzanne Loebl
Macmilan , 1996
Buku Referensi