PLIKUSAS, A.; PUMPUTIS, D. Estimation of the finite population covariance using calibration. Nonlinear Analysis: Modelling and Control, [S. l.], v. 15, n. 3, p. 325–340, 2010. DOI: 10.15388/NA.15.3.14328. Disponível em: https://www.journals.vu.lt/nonlinear-analysis/article/view/14328.. Acesso em: 7 jul. 2024.