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