Os minerais mais perigosos … (in pt). flaviogimenes.wordpress.com / Espaço do Profº. Flávio (2014-10-05). Retrieved on 2014-10-15.
The Other Side Of Crystals: The 9 Deadliest Minerals We’ve Ever Mined (in en). consciousreminder.com (2017-07-22). Retrieved on 2017-07-25.Name ok, no license, "Wiki", backlink to Commons user page
Andrew Tarantola (2014-09-26). The 9 Deadliest Minerals We've Ever Mined (in en). gizmodo.com. Retrieved on 2017-10-29.Name ok, no license, "Wiki", backlink to Commons user page