New Difference Estimator in Two-Phase Sampling using Arbitrary Probabilities. Journal of Statistics, [S. l.], v. 15, 2008. DOI: 10.65463/jstat.2008.133. Disponível em: https://jstat.gcu.edu.pk/index.php/jstat/article/view/133. Acesso em: 11 aug. 2026.