Gypsum (Inventory)/Needle
From LagWiki
References
- Hill, Carol; Paolo Forti (1997) Cave Minerals of the World (Second Edition ed.) National Speleological Society pp 103-104 ISBN: 1-879961-07-5
- Palmer, Arthur N. (2007) Cave Geology CAVE BOOKS, Dayton, OH pp 290-291 ISBN-13: 978-0-939748-66-2, ISBN-10: 0-939748-66-5