Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), petruiov (Expand Search), petroiov (Expand Search), periov (Expand Search)
petruov » petrov (Expand Search), petruuov (Expand Search), petrouov (Expand Search), peruov (Expand Search)
petrv » petrov (Expand Search), petru (Expand Search), petro (Expand Search), petruv (Expand Search), perv (Expand Search)
petriuo » petruiuo (Expand Search), petroiuo (Expand Search), periuo (Expand Search)
petr » petru (Expand Search), petro (Expand Search), per (Expand Search)
petri » petrui (Expand Search), petroi (Expand Search), peri (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 petruov) OR (petrv OR petriov)) OR (petriuo OR ((petr OR petri) OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petriov OR petruov) OR (petrv OR petriov)) OR (petriuo OR ((petr OR petri) OR peter))) o.s.*".