@TechReport{ehkkrw-ce-01,
author = { Alon Efrat and Frank Hoffmann and Christian Knauer and Klaus Kriegel and G{\"u}nter Rote and Carola Wenk },
title = { Covering with Ellipses },
year = { 2001 },
month = { December },
number = { B 01-08 },
institution = { Freie Universit{\"a}t Berlin, Fachbereich Mathematik und Informatik },
}
