الوصول الحر: https://doaj.org/article/cdcd997a27944fcfa0889ff508db3162Test
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e9e766316823505683e1a14cfbfb10e3Testhttps://doi.org/10.1155/2013/847942Test