Newell, Allen (1975). D. Raj Reddy (ed.). A Tutorial on Speech Understanding Systems. In Speech Recognition: Invited Papers Presented at the 1974 IEEE Symposium. New York: Academic. p. 43.
Paul, Frank; Huggel, Christian; Kääb, Andreas (2004). "Combining satellite multispectral image data and a digital elevation model for mapping debris-covered glaciers". Remote Sensing of Environment. 89 (4). Elsevier BV: 510–518. Bibcode:2004RSEnv..89..510P. doi:10.1016/j.rse.2003.11.007. ISSN0034-4257.
Paul, Frank; Huggel, Christian; Kääb, Andreas (2004). "Combining satellite multispectral image data and a digital elevation model for mapping debris-covered glaciers". Remote Sensing of Environment. 89 (4). Elsevier BV: 510–518. Bibcode:2004RSEnv..89..510P. doi:10.1016/j.rse.2003.11.007. ISSN0034-4257.
Paul, Frank; Huggel, Christian; Kääb, Andreas (2004). "Combining satellite multispectral image data and a digital elevation model for mapping debris-covered glaciers". Remote Sensing of Environment. 89 (4). Elsevier BV: 510–518. Bibcode:2004RSEnv..89..510P. doi:10.1016/j.rse.2003.11.007. ISSN0034-4257.