SINGH, H. P.; TRACY, D. S. Estimation of population mean in presence of random non-response in sample surveys. Statistica, [S. l.], v. 61, n. 2, p. 231–248, 2001. DOI: 10.6092/issn.1973-2201/1176. Disponível em: https://rivista-statistica.unibo.it/article/view/1176. Acesso em: 17 oct. 2021.