Drewes F, Habel A, Hoffmann B, Plump D. Manipulation of Graphs, Algebras and Pictures. Essays Dedicated to Hans-Jörg Kreowski on the Occasion of His 60th Birthday. eceasst [Internet]. 2010 Apr. 4 [cited 2025 Jan. 5];26. Available from: https://eceasst.org/index.php/eceasst/article/view/1631