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3. The global water cycle;Berner,1987
4. A quantitative study of five thousand years of volcanism on São Miguel, Azores;Booth;Philos. Trans. R. Soc. Lond.,1978
5. Carvalho, M.R., 1999. Estudo hidrogeológico do maciço vulcânico de Água de Pau/Fogo (São Miguel-Açores). Ph.D. Thesis, Lisbon Univ., Portugal. (in Portuguese, with English Abstr.).