الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4a38bd409022ab00d1e153a48fc88929Testhttps://doi.org/10.1016/s0140-6736Test(17)32457-1
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::af4482f9a451ffa406c2d153b989b818Testhttps://doi.org/10.1016/s0140-6736Test(97)12536-3