Howard, James C.
IPC Science and Technology Press, 1979
Buku Teks
edited by Robert Grossman
Society for Industrial and Applied Mathematics, 1989
eBooks
Whimbey, Arthur
McGraw-Hill, 1981
Buku Teks SO
Artikel Jurnal
Archbold, J.W.
English Language Book Society, 1974
Buku Teks