TY - BOOK AU - Creswell,John W. TI - Research design: qualitative, quantitative, and mixed methods approaches SN - 9781412965569 (cloth) AV - H62 .C6963 2009 PY - 2009///. CY - Los Angeles PB - Sage KW - Social sciences KW - Research KW - Methodology KW - Statistical methods N1 - Includes bibliographical references (p. 237-245) and indexes ER -