Marques, J. EspinhaMarques, José M.Aguiar, Carlos2011-05-242011-05-242010Espinha Marques, J.; Marques, J.M.; Aguiar, C. (2010). A groundwater system in a mountain environment (Serra da Estrela, Portugal). In Ed. Evelpidou, Niki [et al.] Natural Heritage from East to West. Berlin: Springer Verlag. p. 163-168. ISBN 978- 3-642-01576-2978- 3-642-01576-2http://hdl.handle.net/10198/4521Mountains are often recognized as the "world's water towers", due to their exceptional ability to generate water resources or good quality and. frequently, or considerable economic value (e.g. UNESCO IHP-VI Programme: http://www,unesco.org, Aureli 2002).engPortugalGroundwaterbook part