SGEM 2019 : 19th international multidisciplinary scientific geoconference SGEM 2019, 30 June - 6 July, 2019, Albena, Bulgaria. 19, Ecology, economics, education and legislation. Ecology and environmental protection. -- 1st ed. -- Sofia : STEP92 Technology, 2019. -- 1012 s. : grafy, ilustr., tab. -- Bibliografické odkazy. -- ISBN 978-619-7408-86-7 (brož.). -- ISBN 978-619-7408-85-0 online. http://www.sgem.org ekológia * environmentalistika * geoparky * životné prostredie * legislatíva