edited by J. Billingham and
Pergamon Press, 1979
Buku Teks SO
Dick, Steven J.
Cambridge University Press, 1996
Buku Teks
edited by Arnold Hanslmeier, Stephan Kempe and Joseph Seckbach
Springer, 2012
eBooks
Jones, H. Spencer
Macmillan, 1956
Buku Teks
Achenbach, Joel
Simon & Schuster, 1999
Buku Teks