SGEM 2023. 23rd International Multidisciplinary Scientific GeoConference : conference proceedings. 03 - 09 July 2023, Albena, Bulgaria. Issue 1.1 Hydrogeology, Engineering Geology and Geotechnics. 1. vyd. Sofia : STEF 92 Technology, 2023. ISBN 978-619-7603-56-9. ISSN 1314-2704.