CHHAPARWAL, P. .; KUMAR, S. . Improving Efficiencies of Ratio- and Product-type Estimators for Estimating Population Mean for Time-based Survey. Journal of Reliability and Statistical Studies, [S. l.], v. 15, n. 01, p. 325–340, 2022. DOI: 10.13052/jrss0974-8024.15113. Disponível em: https://journals.riverpublishers.com/index.php/JRSS/article/view/20323. Acesso em: 30 may. 2024.