Some useful links
- ProKARSTerra
- Experimental Laboratory of Karstology at NIGGG-BAS
- National Institute of Geophysics, Geodesy and Geography (NIGGG-BAS)
- Bulgarian Academy of Sciences (BAS)
- Foundation Center for Karstology "Vladimir Popov", Sofia
- National Museum of Natural History (BAS), Sofia, Bulgaria
- Ministry of Environment and Water (MOEW, Bulgaria)
- Bulgarian Ministry of Tourism
- Ministry of Education and Science (MES, Bulgaria)
- Executive Forests Agency – Bulgarian Ministry of Agriculture and Food (MAF)
- Directorate of Nature Park “Vrachanski Balkan”, Vratsa, Bulgaria
- Administration of Moravský kras PLA, Blansko, Czech Republic
- Cave Administration of the Czech Republic
- Akiyoshi-dai Quasi-National Park (Mine, Yamaguchi, Japan)
- Yamaguchi University (Japan)
- Zespół Parków Krajobrazowych Województwa Śląskiego, Poland
- UNESCO
- National Commission for UNESCO, Bulgaria
- International Union of Speleology (UIS)
- Bulgarian Federation of Speleology
- Bulgarian Caving Society
- The 13th EuroSpeleo Forum – Sofia`2019
- International Geographic Union (IGU)
- Teteven Municipality
- Municipality of Yablanitsa
- Titan Zlatna Panega Cement AD