Fitriati
STKIP Bina Bangsa Getsempena. Mathematics Department, 2014
Artikel Jurnal
Stephen P. Norris
Sense, 2012
eBooks
Meserve, Bruce
Prentice Hall Inc., 1969
Buku Teks
Rosen, Kenneth H.
McGraw-Hill, 2013
Buku Teks
Fletcher, Peter
PWS-Kent, 1990
Buku Teks