^ abPalmer, Arthur N. (2007). Cave Geology. Dayton, OH: CAVE BOOKS. p. 288. ISBN978-0-939748-66-2.
^ abHill, Carol; Forti, Paolo (1997). Cave Minerals of the World (Second Edition ed.). Huntsville, AL: National Speleological Society. pp. 59–61. ISBN1-879961-07-5.