Cox, D. R. (David Roxbee), author
Science Paparbacks and Methuen, 1962
Buku Teks
Woodroofe, Michael, author
Society for Industrial and Applied Mathematics, 1982
eBooks
Tri Lestari, author
Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Indonesia, 1997
UI - Skripsi (Membership)
Huyck, Alfred P. Van
Chandler-Davis Publishing Company, 1962
Buku Teks
edited by Abdul Khakee, Paola Somma, Huw Thomas
Ashgate, 1999
Buku Teks