Perhaps you should try some spelling variations:
petrov » petro (Expand Search), peterov (Expand Search), petruov (Expand Search), petroov (Expand Search)
petruov » peteruov (Expand Search), petruuov (Expand Search), petrouov (Expand Search)
petroov » peteroov (Expand Search), petruoov (Expand Search), petrooov (Expand Search)
petriov » peteriov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
petr » peter (Expand Search), petru (Expand Search), petro (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (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 (((petruov OR (petroov OR petrov)) OR (petriov OR peteriuiov)) OR (petr OR petri)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petruov OR (petroov OR petrov)) OR (petriov OR peteriuiov)) OR (petr OR petri)) o.s.*".