Glasgow, Joshua, author
Routledge, 2009
Buku Teks
Lindner, C.C., author
CRC Pres, 2009
Buku Teks
editor, Bela Bollobas
North-Holland , 1982
Buku Teks
Laha, R.G., author
John Wiley & Sons, 1979
Buku Teks
Landau, Lev D., author
Pergamon Press, 1986
Buku Teks