Perhaps you should try some spelling variations:
petrov » petro (Expand Search), petriov (Expand Search), petruov (Expand Search), petroov (Expand Search)
petr » petri (Expand Search), petru (Expand Search), petro (Expand Search)
petruo » petriuo (Expand Search), petruuo (Expand Search), petrouo (Expand Search), petru (Expand Search), petro (Expand Search)
petriiuo » petriiiuo (Expand Search), petruiiuo (Expand Search), petroiiuo (Expand Search)
petrui » petriui (Expand Search), petruui (Expand Search), petroui (Expand Search), petri (Expand Search), petru (Expand Search)
petero » peters (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 petr) OR (((petero OR (petruo OR petriiuo)) OR (petrui OR per)) OR peter)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petrov OR petr) OR (((petero OR (petruo OR petriiuo)) OR (petrui OR per)) OR peter)) o.s.*".