الوصول الحر: https://explore.openaire.eu/search/publication?articleId=od_______707::c0dfff37924967941541c94069779f84Testhttps://hdl.handle.net/10900/48849Test
الإتاحة: http://hdl.handle.net/10900/48849Testhttp://nbn-resolving.de/urn:nbn:de:bsz:21-opus-20729Test
الإتاحة: http://nbn-resolving.de/urn:nbn:de:kobv:188-fudissthesis000000103087-9Test