The possibility to add publications from several bib files

Hi Andrey,

You are probably using an old version of moderncv, as the latest version (available on CTAN) is fully compatible with multibib.

Once you have the latest version, there is just one thing that may/need to be tweaked: ensuring the different "bibliographies" appear as subsections of a more general "Publications" section. Basically, you can just copy moderncv's definition of the environment, and replace the call to \section by a call to \subsection, i.e.
\makeatletter
\renewenvironment{thebibliography}[1]%
  {%
    \subsection{\refname}%
    \small%
    \begin{list}{\bibliographyitemlabel}%
      {%
        \setlength{\topsep}{0pt}%
        \setlength{\labelwidth}{\hintscolumnwidth}%
        \setlength{\labelsep}{\separatorcolumnwidth}%
        \leftmargin\labelwidth%
        \advance\leftmargin\labelsep%
        \@openbib@code%
        \usecounter{enumiv}%
        \let\p@enumiv\@empty%
        \renewcommand\theenumiv{\@arabic\c@enumiv}}%
        \sloppy\clubpenalty4000\widowpenalty4000%
  }%
  {%
    \def\@noitemerr{\@latex@warning{Empty `thebibliography' environment}}%
    \end{list}%
  }
\makeatother

Once that is done in the header of your file (i.e. before \begin{document}), let's say you want to separate books from other publications. You then just need to tell moderncv to use multibib accordingly in the header of your resumé:
\usepackage{multibib}
\newcites{book,misc}{{Books},{Others}}

and add something like the next couple of lines in the main part of your .tex file
\section{Publications}
\nocitebook{book1,book2} % cite your books
\bibliographystylebook{plain}
\bibliographybook{publications} % 'publications' is the name of a BibTeX file
\nocitemisc{misc1,misc2,misc3} % cite other elements
\bibliographystylemisc{plain}
\bibliographymisc{publications} % 'publications' is the name of a BibTeX file

If you have any more question, don't hesitate to shout back.
Good luck!