Incoming Resources
- Exploring caves, journeys into the earth, by Nancy Holler Aulenbach and Hazel A. Barton, with Marfé Ferguson Delano
- Surviving the cave, Kristin J. Russo
- Caves, exploring hidden realms, Michael Ray Taylor
- Blind descent, the quest to discover the deepest place on earth /, James M. Tabor
- Entering the stone, on caves and feeling through the dark, Barbara Hurd
- Blind descent, the quest to discover the deepest cave on earth /, James M. Tabor