Bibliography string 'print' undefined

I use biblatex and a special fonencoding for the cyrillic alphabet. Everything works fine, only the bibliography prints an additional, unwanted string 'print' at the end of each item.

Here's my code:

\documentclass[12pt,titlepage]{article}
\usepackage[a4paper]{geometry}
\usepackage[russian,ngerman]{babel}
\usepackage[OT2, T1]{fontenc}
\usepackage[onehalfspacing]{setspace}
\usepackage{times}
\usepackage{csquotes}

\newcommand{\textcyr}[1]{%
{\donothyphenate\fontencoding{OT2}\selectfont #1}}
\newlanguage\nohyphens
\newcommand{\donothyphenate}{%
\language=\nohyphens}

\usepackage[backend=bibtex8,style=mla, citestyle=verbose-ibid]{biblatex} % OPTION:,citestyle=authoryear
\usepackage{filecontents}% to embed the file `myreferences.bib` in your `.tex` file
\usepackage{tabularx}

\begin{filecontents}{biblio.bib}

@book{mant,
  title={Phraseologie im Deutschen und Spanischen: {\"U}berlegungen zum lexikographischen Konzept eines bilingualen phraseologischen W{\"o}rterbuchs am Beispiel deutscher und spanischer Phraseologismen aus dem Bereich" Religion und Volksfr{\"o}mmigkeit"},
  author={Manten, Rilana},
  year={2013},
  publisher={Romanist. Verlag}
}

@article{test,
  title={\textcyr{Reprezentad2iya e1mod2ii {\guillemotleft}smekh{\guillemotright} v russkoi0  i belorusskoi0 frazeologii}},
  author={\textcyr{Testova, T.A.}},
     journal={\textcyr{Minsk: RIVSh}},
  year={2010}
 }

\end{filecontents}

\addbibresource{biblio.bib}

\begin{document}

This is a test\footnote{\cite{test} and \cite{mant}}

\printbibliography

\end{document}

I also get a warning: pdflatex x> Package biblatex warning: Bibliography string 'print' undefined at entry 'test'....

And it sais that for each entry... The output looks like this:

Does anyone have an idea what's wrong with my code and how I can get rid of the 'print' string?