Copyright (C) 2014 Edward V. Emelianov, Alena V. Emelianova

Permission is granted to copy, distribute and/or modify this document under the
terms of the:
    - GNU Free Documentation License, Version 1.3 or any later version
      published by the Free Software Foundation; with no Invariant Sections, 
      no Front-Cover Texts, and no Back-Cover Texts;
OR
    - Creative Commons Attribution-ShareAlike 4.0 International License.

// You may comply with either license or both

Text of FDL license in english is included into document