1. Czech Academy of Sciences Institute of Geology Prague Czech Republic
2. Institute of Geology and Paleontology, Faculty of Science Charles University Prague Czech Republic
3. U.S. Geological Survey Denver CO USA
4. Environmental Geology, Natural Resources Management Department New Mexico Highlands University Las Vegas NM USA
5. U.S. Geological Survey Menlo Park CA USA
6. Department of Geological and Mining Engineering and Sciences Michigan Technological University Houghton MI USA