DR. SANJIB CHOUDHURY; BHUPENDRA KUMAR SINGH. An Efficient Class of Ratio-Cum-Dual to Product Estimator of Finite Population Mean in Sample Surveys. Global Journal of Science Frontier Research, [S. l.], v. 12, n. F12, p. 1–11, 2012. Disponível em: https://journalofscience.org/index.php/GJSFR/article/view/669. Acesso em: 5 may. 2024.