@book{6667, address = {Mahwah, N.J. :}, url = {http://www.loc.gov/catdir/enhancements/fy0745/2003040785-d.html}, year = {2003.}, publisher = {L. Erlbaum Associates,}, author = {Brace, Nicola. and Kemp, Richard.}, title = {SPSS for psychologists :}, edition = {2nd ed.} }