الوصول الحر: https://research.chalmers.se/publication/523677Testhttps://research.chalmers.se/publication/523608Testhttps://research.chalmers.se/publication/523677/file/523677_Fulltext.pdfTest
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=pmid________::6384acff5ae30d7367d6a9c03e76255aTesthttp://europepmc.org/articles/PMC6603209Test