About this article
Published Online: Dec 11, 2014
Page range: 133 - 137
Received: May 22, 2014
DOI: https://doi.org/10.2478/aupcsm-2014-0010
© by Dariusz Cichoń
This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License.
A new proof of the Ficken criterion is given together with a comment concerning the known proofs and related results