Sturm, Helmut. 1978. Zur Ökologie der andinen Paramoregion. Biogeographica 14: 121 pp. W. Junk. The Hague. [On the ecology of the Andean Paramo region] (Shared for non-commercial educational purposes only - All rights belong to authors, publishers and respective owners - http://www.springer.com/la/book/9789061932154)