Incoming Resources
- Sinkholes, by Vanessa Black
- Sinkholes, by Eric Reeder
- Underland, a deep time journey, Robert Macfarlane
- Caves, by Emily K. Green
- Caves, written by Nell Cross Beckerman ; illustrated by Kalen Chock
- Layers of stone, how Earth's biggest caves formed, Daniel R. Faust
- Caves, by Rebecca Pettiford
- Caves, by Sally M. Walker
- I wonder why stalactites hang down and other questions about caves, Jackie Gaff
- Worlds beneath our feet, writer, Daniel Kenis
- Caves, Claire Llewellyn
- Studying sinkholes, by Tamra B. Orr
- Extreme cave diving, a production of Nova and National Geographic Television ; produced and directed by James Barrat