M AL-KAASAB, M.; AL-EMAT, A. On The Effect of Stratification When Two Independent Stratifying Variables Are Used. IRAQI JOURNAL OF STATISTICAL SCIENCES, [S. l.], v. 13, n. 3, p. 133–149, 2013. DOI: 10.33899/iqjoss.2013.081295. Disponível em: https://tanmiyat.uomosul.edu.iq/index.php/stats/article/view/29332. Acesso em: 6 sep. 2025.