Creswell John W. Educational Research-Planning, Conducting, and Evaluating Quantitative and Qualitative Research-

4th edition. — Pearson, 2011. — 672 p.This book is the only introductory educational research text to offer a truly balanced and integrated treatment of both quantitative and qualitative methods. Written in clear and practical language, Educational Research will help its readers get started doing their own research and will also help them become better readers of research.