الوصول الحر: https://doaj.org/article/8f353fe344d34a1b8df61319e91608c4Test
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f7766aea66a81745ae45a69772db08d1Testhttp://europepmc.org/articles/PMC8065631Test