Creswell, John W. Educational research : planning, conducting, and evaluating quantitive and qualitative research / John W. Creswell - 2nd. ed. - Upper Saddle River, N.J. : Pearson , 2005 - 623 p. : il. ; 26 cm. Includes: index ISBN: 013112790X Subjects--Topical Terms: Educación --- Investigación LC Class. No.: LB 1028 / C742 2005