Mehrotra, P. V., Mehrotra, R. N., & Sukhia, S. P. Elements of educational research (Ed.3 rev.).

Mehrotra, P V., R N. Mehrotra, and S P. Sukhia. Elements of Educational Research. Ed.3 rev. Ahmedabad, Allied Publishers.

Mehrotra, P V., et al. Elements of Educational Research. Ed.3 rev.