zachar.uni-pannon.hu
simon@dcs.uni-pannon.hu
mmaroti@math.u-szeged.hu
© 2020 Gergely Zachár, Gyula Simon, Miklós Maróti, published by Professor Subhas Chandra MukhopadhyayThis work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.