À propos de cet article
Publié en ligne: 28 déc. 2020
Pages: 83 - 88
Reçu: 02 janv. 2020
Accepté: 17 janv. 2020
DOI: https://doi.org/10.2478/auom-2020-0035
Mots clés
© 2020 Grigore Călugăreanu et al., published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
We show that for two 2