Wing, G.M., 1923- , author
Society for Industrial and Applied Mathematics, 1991
eBooks
Hochstadt, Harry, author
John Wiley & Sons, 1973
Buku Teks SO
Zemyan, Stephen M., author
Springer, 2012
eBooks
Polyanin, Andrei D., author
Chapman &Hall/CRC, 2008
Buku Referensi
edited by Christopher T.H. Baker, Geoffrey F. Miller
Academic Press, 1982
Buku Teks SO