Adhikary, Arun Kumar2013-07-172013-07-171996Communication in Statitics Theory and Method , v 25, no 8, p 1757-1768http://hdl.handle.net/10263/5540enDuality theoremFerkasFinite populationRejective IPPS sampling planSampling designLemmaOn non-negativity of the nearest proportional to size sampling designArticle