APA (7e ed.) Bronvermelding

Beltran, D. G. (1973). A method of determining economical sample size for sample surveys [microform]. Photoduplication Service.

Chicago (17e ed.) Bronvermelding

Beltran, Disodado G. A Method of Determining Economical Sample Size for Sample Surveys [microform]. Quezon City: Photoduplication Service, 1973.

MLA (9e ed.) Bronvermelding

Beltran, Disodado G. A Method of Determining Economical Sample Size for Sample Surveys [microform]. Photoduplication Service, 1973.