Perhaps you should try some spelling variations:
petris » petri (Expand Search), petriis (Expand Search), petruis (Expand Search), petrois (Expand Search)
petruov » petrov (Expand Search), petriuov (Expand Search), petruuov (Expand Search), petrouov (Expand Search)
petero » peters (Expand Search), petro (Expand Search)
petrio » petri (Expand Search), petro (Expand Search), petriio (Expand Search), petruio (Expand Search), petroio (Expand Search)
petriuv » petriiuv (Expand Search), petruiuv (Expand Search), petroiuv (Expand Search)
petr » petri (Expand Search), petru (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 (((petris OR petruov) OR petriuv) OR (((petero OR petero) OR petrio) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petris OR petruov) OR petriuv) OR (((petero OR petero) OR petrio) OR (petr OR peter))) o.s.*".