Commentary on S. Kumar and P. Chhaparwal, 2016. A robust unbiased dual to product estimator for population mean through Modified Maximum Likelihood in simple random sampling, Cogent Mathematics, 3:1168070

In the manuscript entitled "A Robust Unbiased Dual to Product Estimator for Population Mean through Modified Maximum Likelihood in Simple Random Sampling", several publications and derivations which belong to E. Oral were used without sufficient acknowledgment or citation. In this paper, we comment on the manuscript, and refer the reader to the original sources of the derivations and publications