1. Systematic review of the genus Skolithos;Alpert S. P.;Journal of Paleontology,1974
2. Anonymous. 1929. City officials explore cave beneath Loop. Minneapolis Morning Tribune February 21.
3. Boxmeyer D. 1997. Mean streets will open up and swallow you. St. Paul Pioneer Press July 16.
4. Brewer J. 2010. Pedestrian plunges into sidewalk sinkhole St. Paul man suffers bumps bruises in fall; mishap blamed on water leak. St. Paul Pioneer Press September 8.
5. What happened to Fountain Cave—The real birthplace of St. Paul?;Brick G. A.;Ramsey County History,1995