Beltran, D. G. (1973). A method of determining economical sample size for sample surveys [microform]. Photoduplication Service.
Chicago-viite (17. p.)Beltran, Disodado G. A Method of Determining Economical Sample Size for Sample Surveys [microform]. Quezon City: Photoduplication Service, 1973.
MLA-viite (9. p.)Beltran, Disodado G. A Method of Determining Economical Sample Size for Sample Surveys [microform]. Photoduplication Service, 1973.
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