Perhaps you should try some spelling variations:
perov » petrov (Expand Search)
petrovov » petrov (Expand Search), petrovvov (Expand Search), petrivov (Expand Search), petruvov (Expand Search), peterovov (Expand Search), petriovov (Expand Search), petruovov (Expand Search)
petroov » petrovov (Expand Search), petriov (Expand Search), petruov (Expand Search), peteroov (Expand Search), petrioov (Expand Search), petruoov (Expand Search)
petro » petrov (Expand Search), petri (Expand Search), petru (Expand Search), petero (Expand Search), petrio (Expand Search), petruo (Expand Search)
petriu » peteriu (Expand Search), petriiu (Expand Search), petruiu (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (Expand Search)

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: fop ((perov OR (petroov OR petrovov)) OR (petriu OR (petro OR petr))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((perov OR (petroov OR petrovov)) OR (petriu OR (petro OR petr))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((perov OR (petroov OR petrovov)) OR (petriu OR (petro OR petr))) o.s.*.