1. Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania 16802
2. Geology Department, Carleton College, Northfield, Minnesota 55057
3. Istituto Italiano di Speleologia, Frasassi Section, Viale Verdi 10, 60035 Jesi, Italy
4. Gruppo Speleologico CAI, Via Alfieri 9, 60044 Fabriano, Italy