Volcanoes and their activity. Translated from the 2d German ed. by E.A. Vincent. Vulkane und ihre Tätigkeit. English Rittmann, Alfred, 1893-1980. Volcanoes. QE522 .R613 551.21 RIV New York, Interscience Publishers, 1962. 1962. 1962 Text 305 p. eng engger