Usha, M. (1993). Sampling schemes providing unbiased ratio and regression estimators. Dept of statistics, University of Kerala.
استشهاد بنمط شيكاغوUsha, M.S. Sampling Schemes Providing Unbiased Ratio and Regression Estimators. Thiruvananthapuram: Dept of statistics, University of Kerala, 1993.
MLA استشهادUsha, M.S. Sampling Schemes Providing Unbiased Ratio and Regression Estimators. Dept of statistics, University of Kerala, 1993.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.