Perhaps you should try some spelling variations:
petrov » petro (Expand Search), petruov (Expand Search), petroov (Expand Search), perov (Expand Search)
petrow » petro (Expand Search), petrowna (Expand Search), petruow (Expand Search), petroow (Expand Search), perow (Expand Search)
petroiiv » petruoiiv (Expand Search), petrooiiv (Expand Search), peroiiv (Expand Search)
petr » petru (Expand Search), petro (Expand Search), per (Expand Search)
petri » petrui (Expand Search), petroi (Expand Search), peri (Expand Search)
petrui » petruui (Expand Search), petroui (Expand Search), perui (Expand Search), petru (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 (((periiv OR petroiiv) OR petrov) OR (petrow OR ((petr OR (petri OR petrui)) OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((periiv OR petroiiv) OR petrov) OR (petrow OR ((petr OR (petri OR petrui)) OR peter))) o.s.*".