1 2 3 Curriculum vitae, retrieved 2017-01-01. ↑ Hitzeroth, Manfred (January 11, 2011), "Vom Affensattel zum Storchenschnabel", Oberhessische Presse (in German) ↑ Ilka Agricola at the Mathematics Genealogy Project ↑ Communications in Mathematics, publisher home page, retrieved 2017-01-01. ↑ Gabel, Tim (December 20, 2013), "Mit Gauß unter den Weihnachtsbaum" (PDF), Oberhessische Presse (in German) . ↑ Lehrende aus Gießen und Marburg erhalten Ars legendi-Fakultätenpreis (in German), Hessian Ministry for Science and the Arts, April 11, 2016 . ↑ Review of Globale Analysis (Vieweg, 2001) by Jürgen Eichhorn, MR1823409. ↑ Review of Elementary geometry by William J. Satzer, Mathematical Association of America, April 30, 2008.