Perhaps you should try some spelling variations:
petriov » petrov (Expand Search)
petrv » petrov (Expand Search), petru (Expand Search), petr (Expand Search)
petruv » petru (Expand Search), petrov (Expand Search)
peterv » peter (Expand Search), peters (Expand Search)
peteri » peterdi (Expand Search), peter (Expand Search), peters (Expand Search)
petero » peter (Expand Search), peters (Expand Search), petro (Expand Search)
petriu » petru (Expand Search), petris (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 ((petrv OR petruv) OR peterv)) OR (((peteri OR petero) OR petriu) OR petri)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriov OR ((petrv OR petruv) OR peterv)) OR (((peteri OR petero) OR petriu) OR petri)) o.s.*".