Perhaps you should try some spelling variations:
petrov » petro (Expand Search), petruov (Expand Search), petroov (Expand Search), perov (Expand Search)
petero » peters (Expand Search), petro (Expand Search)
petrii » petris (Expand Search), petruii (Expand Search), petroii (Expand Search), perii (Expand Search)
petruo » petru (Expand Search), petro (Expand Search), petruuo (Expand Search), petrouo (Expand Search), peruo (Expand Search)
petri » petrui (Expand Search), petroi (Expand Search), peri (Expand Search)
petr » petru (Expand Search), petro (Expand Search), per (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 (((petero OR (petrii OR petri)) OR (petruo OR peteruo)) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (petrov OR (((petero OR (petrii OR petri)) OR (petruo OR peteruo)) OR (petr OR peter))) o.s.*".