الإتاحة: https://doi.org/10.17615/9gxm-pq83Testhttps://cdr.lib.unc.edu/downloads/zc77sx19p?file=thumbnailTesthttps://cdr.lib.unc.edu/downloads/zc77sx19pTest
الإتاحة: https://doi.org/10.17615/nat6-2p24Testhttps://cdr.lib.unc.edu/downloads/gm80j2320?file=thumbnailTesthttps://cdr.lib.unc.edu/downloads/gm80j2320Test