الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::64618b5461528941c97dcf21197577dbTesthttp://link.springer.com/article/10.1186/s12884-020-03122-4Test
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::bd1e06c442dd801b95c468bf15a69e78Testhttp://europepmc.org/articles/PMC4148545Test