TY - BOOK AU - Creswell,John W. TI - Research design : qualitative, quantitative, and mixed methods approaches SN - 9781412965569 (cloth) U1 - 300.72 C923R 2009 22 PY - 2009/// CY - Thousand Oaks, Calif. PB - Sage Publications KW - Social sciences KW - Research KW - Methodology KW - Statistical methods ER -