Perhaps you should try some spelling variations:
petriv » petris (Expand Search), petruiv (Expand Search), petroiv (Expand Search), periv (Expand Search)
peters » petersen (Expand Search)
petrov » petro (Expand Search), petruov (Expand Search), petroov (Expand Search), perov (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 ((petriv OR peruuiv) OR (((peters OR (petri OR petrov)) OR petruo) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriv OR peruuiv) OR (((peters OR (petri OR petrov)) OR petruo) OR (petr OR peter))) o.s.*".