@inproceedings{15ea759fd43343ee838afd0bd230fa9a,
title = "Operationalization of the Metadata Element {"}Difficulty{"}",
author = "Margit Kastner and Gerhard Furtm{\"u}ller",
year = "2007",
month = jul,
day = "1",
language = "Deutsch ({\"O}sterreich)",
isbn = "978-0-7695-2916-5",
pages = "608 -- 612",
editor = "{J. M.Spector, D. G. Sampson, T.Okamato, Kinshuk, St. A. Cerri, M. Ueno, A. Kashihara}",
booktitle = "The Seventh IEEE International Conference on Advanced Learning Technologies",
publisher = "IEEE Computer Society Press",
}