TY  - BOOK
AU  - Creswell, John W. 
TI  - Research design: qualitative, quantitative, and mixed methods approaches 
SN  - 9781506386706   Pbk. 
AV  - H 62 C74 2018 CHS 
PY  - 2018///.
CY  - Los Angeles
PB  - SAGE, 
KW  - Social sciences--Research--Methodology
KW  - Social sciences--Statistical methods
N1  - Includes bibliographical references and index
ER  -