Perhaps you should try some spelling variations:
petrv » peterv (Expand Search), petriv (Expand Search), petruv (Expand Search)
petruv » peteruv (Expand Search), petriuv (Expand Search), petruuv (Expand Search)
petruov » peteruov (Expand Search), petriuov (Expand Search), petruuov (Expand Search)
petroi » peteroi (Expand Search), petrioi (Expand Search), petruoi (Expand Search)
petrui » peterui (Expand Search), petriui (Expand Search), petruui (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (Expand Search)

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: fop ((petrv OR petruv) OR (petruov OR ((((petroi OR peteroi) OR petrui) OR petrui) OR petr))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petrv OR petruv) OR (petruov OR ((((petroi OR peteroi) OR petrui) OR petrui) OR petr))) o.s.*".