@inbook{0272ec60d5764496876e96caa4013219,
title = "A comparison of techniques for calculating gradient and aspect from a gridded digital elevation model",
keywords = "ADLIB-ART-201, NRS",
author = "A.K. Skidmore",
year = "2006",
language = "English",
booktitle = "Classics from IJGIS : 20 years of the International Journal of Geographical Information Science and Systems. / ed. by. P.F. Fisher. Boca Raton : CRC, 2006. ISBN: 0-8493-7042-6. pp 97-110. Originally published in: International journal of Geographic information systems, 3(1989)4, pp. 323-334",
publisher = "Chapman and Hall/CRC",
}