An Efficient Class of Dual to Product-Cum- Dual to Ratio Estimators of Finite Population Mean in Sample Surveys. Global Journal of Science Frontier Research, [S. l.], v. 12, n. F3, p. 25–33, 2012. Disponível em: https://www.journalofscience.org/index.php/GJSFR/article/view/604. Acesso em: 13 feb. 2026.