الوصول الحر: https://lup.lub.lu.se/record/686389Testhttp://dx.doi.org/10.1038/sj.ki.5001515Test
الإتاحة: https://doi.org/10.1371/journal.pmed.1003691Testhttp://hdl.handle.net/10281/320153Test
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f532fe597469725c51a3f7ae6f5eff27Testhttps://doi.org/10.1371/journal.pmed.1003691Test