الوصول الحر: https://doaj.org/article/31a49e1fe8dc46a583813ab0f1bb8ffdTest
الوصول الحر: https://doaj.org/article/13f878cad9eb4100bfbbd5566152901aTest
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ce6d50b44ac615958f2bc509c898ccacTesthttps://doi.org/10.1136/bmjopen-2021-052250Test