الإتاحة: http://resolver.sub.uni-goettingen.de/purl?027052486_0006%7CLOG_0141Test
الإتاحة: http://resolver.sub.uni-goettingen.de/purl?027061086_0025%7CLOG_0388Test
الوصول الحر: http://yadda.icm.edu.pl/baztech/element/bwmeta1.element.baztech-article-BPBE-0004-0006Test
الإتاحة: https://doi.org/10.1007/978-3-662-43100-9Test
الإتاحة: https://doi.org/10.1016/0006-291xTest(78)91546-2https://api.elsevier.com/content/article/PII:0006291X78915462?httpAccept=text/xmlTesthttps://api.elsevier.com/content/article/PII:0006291X78915462?httpAccept=text/plainTest