Abd Alsalam، N. M. M. (2014). Disproportional Stratification Component of Design Effect: Case of Equal Strata Variances and Different Strata Means. مجلة دراسات حوض النيل، مج8, ع16 ، 41 - 54. مسترجع من http://search.mandumah.com/Record/609620
Abd Alsalam، Nidal Mohamed Mustafa. "Disproportional Stratification Component of Design Effect: Case of Equal Strata Variances and Different Strata Means." مجلة دراسات حوض النيل مج8, ع16 (2014): 41 - 54. مسترجع من http://search.mandumah.com/Record/609620