Aggarwal, J. C. 1991. Educational Research: An Introduction. New Delhi: Arya Book Depot.
Aggarwal, Y. P. 1988. Better Sampling Concepts: Techniques and Evaluations. New Delhi: Sterling Publishers.
Anastasi, A. 1982. Psychological Treating (5th ed.). New York: Macmillan.
Ary, D., G. J. Luch and A. Razavich. 1972. Introduction to Research in Education. New York: Holt, Rinehart & Winston, Inc.
Barr, A. S., R. A. Davis and P. O. Johnson. 1953. Educational Research and Appraisal. Chicago: J. B. Lippincott Co.
Best, J. W. 1977. Research in Education. Englewood Cliffs: Prentice Hall Inc.
Best, J. W. and J. V. Kahn. 1986. Research in Education. Prentice Hall: New Delhi.
Blacock, H. M. and A. B. Blacock. 1971. Methodology in Social Research ...