Gaya APA

GALL, M, D. et al (2007). EDUCATIONAL RESEARCH AN INTRODUCTION EIGHT EDITION (ED. 8). USA: PEARSON PENICE HALL.

Gaya MLA

GALL, MEREDITH, D.. et al. "EDUCATIONAL RESEARCH AN INTRODUCTION EIGHT EDITION". ED. 8 USA: PEARSON PENICE HALL, 2007. Text.