M Al-Kaasab M, Al-Emat A. On The Effect of Stratification When Two Independent Stratifying Variables Are Used. IQJOSS [Internet]. 2025 Jun. 25 [cited 2025 Aug. 3];13(3):133-49. Available from: https://rjps.uomosul.edu.iq/index.php/stats/article/view/20878