Perhaps you should try some spelling variations:
petriiov » petrov (Expand Search), peteriiov (Expand Search), petriiiov (Expand Search), petruiiov (Expand Search)
petruiov » petrov (Expand Search), peteruiov (Expand Search), petriuiov (Expand Search), petruuiov (Expand Search)
petriiiov » peteriiiov (Expand Search), petriiiiov (Expand Search), petruiiiov (Expand Search)
petroi » peteroi (Expand Search), petrioi (Expand Search), petruoi (Expand Search)
petriuio » peteriuio (Expand Search), petriiuio (Expand Search), petruiuio (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (Expand Search)

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: fop ((((petriiov OR petriiiov) OR petruiov) OR petriiiov) OR ((petroi OR petriuio) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petriiov OR petriiiov) OR petruiov) OR petriiiov) OR ((petroi OR petriuio) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((((petriiov OR petriiiov) OR petruiov) OR petriiiov) OR ((petroi OR petriuio) OR petr)) o.s.*.