Perhaps you should try some spelling variations:
petrovov » petrov (Expand Search), petrovvov (Expand Search), petruvov (Expand Search), peterovov (Expand Search), petruovov (Expand Search), perovov (Expand Search)
petroov » petrovov (Expand Search), petruov (Expand Search), peteroov (Expand Search), petruoov (Expand Search), peroov (Expand Search)
petro » petrov (Expand Search), petru (Expand Search), petero (Expand Search), petruo (Expand Search), pero (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), peri (Expand Search)
petr » peter (Expand Search), petru (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 ((petroov OR petrovov) OR (petri OR (petro OR petr))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petroov OR petrovov) OR (petri OR (petro OR petr))) o.s.*".