Perhaps you should try some spelling variations:
petrov » petro (Expand Search), petriov (Expand Search), petruov (Expand Search), petroov (Expand Search)
petrui » petri (Expand Search), petru (Expand Search), petriui (Expand Search), petruui (Expand Search), petroui (Expand Search)
petrio » petri (Expand Search), petris (Expand Search), petro (Expand Search), petriio (Expand Search), petruio (Expand Search), petroio (Expand Search)
petruuiv » petriuuiv (Expand Search), petruuuiv (Expand Search), petrouuiv (Expand Search)
petr » petri (Expand Search), petru (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 ((petruuiv OR petrov) OR ((petrui OR petrio) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruuiv OR petrov) OR ((petrui OR petrio) OR (petr OR peter))) o.s.*".