Ref.: Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 112.
Bulletin de la Société française de Minéralogie Cristallo (1974): 97: 507.
Eckel, Edwin B. (1997) "Minerals of Colorado, updated & revised": 14.