AUDU AHMED; ADEDAYO AMOS ADEWARA; RAN VIJAY KUMAR SINGH. Improved Class of Ratio Estimators for Finite Population Variance. Global Journal of Science Frontier Research, [S. l.], v. 16, n. F2, p. 17–24, 2016. Disponível em: https://journalofscience.org/index.php/GJSFR/article/view/1754. Acesso em: 4 may. 2024.