Authors
Paolo Lipparini
Dipartimento Produttivo di Matematica, Viale della Ricerca Scientifica, Università di Roma “Tor Vergata”,, Rome, Italy
© 2018 Paolo Lipparini, published by University of Silesia in Katowice, Institute of Mathematics
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.