1. Barthlott, W., Burstedde, K., Geffert, J.L., Ibisch, P.L., et al. 2015: Biogeography and Biodiversity of Cacti. Schumannia 7: 205 S.
2. Besler, H. 1972: Klimaverhältnisse und klimamorphologische Zonierung der zentralen Namib. Stuttgarter Geogr. Stud. 83
3. Breckle, S.-W, Veste, M., Yair, A. (eds.): 2008: Arid dune ecosystems - The Nizana Sands in the Negev desert. Ecol. Stud., vol. 200, 475p.
4. Crowley, G. M. 1994: Quaternary soil salinity events and Australian vegetation history. Quarternary Science Reviews 13: 15-22
5. Dinger, B.E. & Patten, D.T. 1974: Carbon dioxide exchange and transpiration in species of Echinocereus (Cactaceae) as related to their distribution within the Pialeno Mountains, Arizona. Oecologia 14: 389-411.