الوصول الحر: https://explore.openaire.eu/search/publication?articleId=od______9626::5fea3e5887270cc81dc4dcedb13029b0Test
الإتاحة: http://research.bfu.bg:8080/jspui/handle/123456789/702Testhttp://www.bposoki.bg/bg/2016/broy-2Test