2[1]Breakweel, G, Hammond, S& Fife - Schaw, e Research methods in psychology,Sage Publications. 1995
3[2]McQueen,R. & Knussen,C. Research methods in psychology:a practica introduction,Prentice Hall Europe. 1999
4[3]Krathwohl, D. R. Methods of educational and social science research: An integrated approach[M]. 2nd Ed. AddisonWesley Educational Publisher, I nc. 1998
5[4]Lundin,R. W. Theories and systems of psychology. Toronto:Heath andCompany. 1991
6[5]Kilpatrick,J. Variables and methodologies in research in problem solving, In Mathematical problem solving, ed. by L. Hatfield, Cambridge Univevsity Pres. 1978
7[6]Patton,M. Qualitative evaluation and research methods. 2nd Ed. Newbury Park:sage. 1990
8[7]Guba, E. G (Eds) The paradigm dialogue. Newbury Park:ge. 1990
9[8]Jacob,E Qualitative research traditions: a review. Review of Educational Research, 1987,57 ( 1 ): 1 - 50
10[9]Creswell, J. W. Research design: qualitative & quantitative approaches. Newbury park: sage. 1994
