Perhaps you should try some spelling variations:
petrov » petro (Expand Search), petriov (Expand Search), petruov (Expand Search), petroov (Expand Search)
petruuv » petriuuv (Expand Search), petruuuv (Expand Search), petrouuv (Expand Search)
petrouuv » petriouuv (Expand Search), petruouuv (Expand Search), petroouuv (Expand Search)
petroio » petrioio (Expand Search), petruoio (Expand Search), petrooio (Expand Search)
petr » petri (Expand Search), petru (Expand Search), petro (Expand Search)
peteri » peterdi (Expand Search), petri (Expand Search), peters (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 ((petrov OR (petruuv OR petrouuv)) OR (petroio OR (petr OR (peteri OR peter)))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petrov OR (petruuv OR petrouuv)) OR (petroio OR (petr OR (peteri OR peter)))) o.s.*".