Mapping as a solution?
 Artikel Jurnal
Eagle, Chester
Mapping the paddocks
McPhee Gribble/Penguins Books, 1985
 Buku Teks SO
Burton, Sharon
Software solutions: concepts and applications
Houghton-Mifflin, 1992
 Buku Teks SO
Altwaijri, Abdulaziz Othman
Child delinquency: the problem and the solutions
ISESCO , 1997
 Buku Teks
Problems in mathematics: with hints and solutions
by V. Govorov ... [and others]; edited by A.L. Prilepko
MIR, 1986
 Buku Teks SO