Perhaps you should try some spelling variations:
petrov » petro (Expand Search), petriov (Expand Search), petruov (Expand Search), petroov (Expand Search)
pero » petro (Expand Search), per (Expand Search), pro (Expand Search)
petrui » petri (Expand Search), petru (Expand Search), petriui (Expand Search), petruui (Expand Search), petroui (Expand Search)
petruuv » petriuuv (Expand Search), petruuuv (Expand Search), petrouuv (Expand Search)
petruuo » petriuuo (Expand Search), petruuuo (Expand Search), petrouuo (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 ((petrov OR petruuv) OR ((((pero OR petruuo) OR petruuo) OR petrui) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petrov OR petruuv) OR ((((pero OR petruuo) OR petruuo) OR petrui) OR (petr OR peter))) o.s.*".