Perhaps you should try some spelling variations:
petriiov » petrov (Expand Search), peteriiov (Expand Search), petriiiov (Expand Search), petruiiov (Expand Search)
peteroio » peterdi (Expand Search)
petrouv » peterouv (Expand Search), petriouv (Expand Search), petruouv (Expand Search)
petruov » peteruov (Expand Search), petriuov (Expand Search), petruuov (Expand Search)
petroi » peteroi (Expand Search), petrioi (Expand Search), petruoi (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 (((petrouv OR petriiov) OR petruov) OR (((petroi OR peteroio) OR peteroio) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petrouv OR petriiov) OR petruov) OR (((petroi OR peteroio) OR peteroio) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petrouv OR petriiov) OR petruov) OR (((petroi OR peteroio) OR peteroio) OR petr)) o.s.*.