Perhaps you should try some spelling variations:
petrov » peterov (Expand Search), petriov (Expand Search), petroov (Expand Search)
petriiov » peteriiov (Expand Search), petriiiov (Expand Search), petroiiov (Expand Search)
petruiov » peteruiov (Expand Search), petriuiov (Expand Search), petrouiov (Expand Search)
petru » peteru (Expand Search), petriu (Expand Search), petrou (Expand Search)
petriu » peteriu (Expand Search), petriiu (Expand Search), petroiu (Expand Search)
petr » peter (Expand Search), petri (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 ((petrov OR (petriiov OR petruiov)) OR ((pero OR (petru OR (petriu OR periu))) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petrov OR (petriiov OR petruiov)) OR ((pero OR (petru OR (petriu OR periu))) OR petr)) o.s.*".