الوصول الحر: https://doaj.org/article/f5d95f98e0734deda11c0af66eea4975Test
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c4434f4e768b4d0499e258d8252ce06bTesthttp://europepmc.org/articles/PMC6637291Test