TY - BOOK AU - Creswell,John W TI - Research design: qualitative, quantitative, and mixed methods approaches SN - 9781412965576 / AV - H62 C715 R4 2009 PY - 2009/// CY - Thousand Oaks, Calif. PB - Sage Publications KW - Social sciences KW - Research KW - Methodology KW - Statistical methods ER -