Παραπομπή APA

Usha, M. (1993). Sampling schemes providing unbiased ratio and regression estimators. Dept of statistics, University of Kerala.

Παραπομπή Chicago Style

Usha, M.S. Sampling Schemes Providing Unbiased Ratio and Regression Estimators. Thiruvananthapuram: Dept of statistics, University of Kerala, 1993.

Παραπομπή MLA

Usha, M.S. Sampling Schemes Providing Unbiased Ratio and Regression Estimators. Dept of statistics, University of Kerala, 1993.