Dill, H.G., Bosse, H.-R., Henning, K.-H., Fricke, A., and Ahrendt, H. (1997): Mineralogical and chemical variations in hypogene and supergene kaolin deposits in a mobile fold belt the Central Andes of northwestern Peru. Mineralium Deposita 32, 149-163.
(TL) indicates type locality. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
Folie, K., P. Gentile, M. Hanke & I. Rocchetti (2010): Mineralien aus der Umgebung des Pfitscher Jochs in Südtirol (II). Mineralien-Welt 21 (4), 42-67.