Perhaps you should try some spelling variations:
perov » petrov (Expand Search)
petroiov » petrov (Expand Search), peteroiov (Expand Search), petrioiov (Expand Search), petrooiov (Expand Search)
petriov » peteriov (Expand Search), petriiov (Expand Search), petroiov (Expand Search)
petrouiov » peterouiov (Expand Search), petriouiov (Expand Search), petroouiov (Expand Search)
petru » peteru (Expand Search), petriu (Expand Search), petrou (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petro (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 (((perov OR (petriov OR petroiov)) OR petrouiov) OR (((petru OR pero) OR per) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((perov OR (petriov OR petroiov)) OR petrouiov) OR (((petru OR pero) OR per) OR petr)) o.s.*".