Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), petriiov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
peters » petersen (Expand Search)
petrioi » petriioi (Expand Search), petruioi (Expand Search), petroioi (Expand Search)
petriio » petriiio (Expand Search), petruiio (Expand Search), petroiio (Expand Search)
petruiio » petriuiio (Expand Search), petruuiio (Expand Search), petrouiio (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 (petriov OR (((petrioi OR peters) OR (petriio OR petruiio)) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (petriov OR (((petrioi OR peters) OR (petriio OR petruiio)) OR (petr OR peter))) o.s.*".