C. Mahaney William et al., Late Quaternary deglaciation and Neoglaciation of the Humboldt Massif,northern Venezuelan Andes, Zeitschrift fur Geomorphologie. Supplementband Zeitschrift fur Geomorphologie. Supplement;Zeitschrift fur Geomorphologie. Supplementary issue Annals of geomorphology. Supplement;Annales de geomorphologie. Supplement, 122, 2000, pp. 209-226