مقالة · مجلة · 2009
Vera Halpern, Orikomaba Obunge, Folasade Tolulope Ogunsola, Sakiru Otusanya, John Umo-Otong, Chin-Hua Wang و1 آخرون
BMC Medical Research Methodology
اقرأه10.1186/1471-2288-9-44
كما طُبع: Folasade Ogunsola