pid type title authors mentors source_title published_date url doi isbn issn eissn rgn:1643 "journal article" "Integration of photovoltaic electricity with shallow geothermal systems for residential microgrids : proof of concept and techno-economic analysis with RES2GEO model" "Perković, Luka; Leko, Domagoj; Lekić Brettschneider, Amalia; Mikulčić, Hrvoje; Varbanov, Petar S."