edited by G. Adomian
Academic Press, 1980
Buku Teks
Narayan Bhat, U.
John Wiley & Sons, 1972
Buku Teks
Osaki, Shunji
Springer-Verlag, 1992
Buku Teks
Lamberton, Damien
Chapman & Hall/CRC , 2008
Buku Teks
Morrison, Donald F.
Prentice-Hall, 1983
Buku Teks