Perhaps you should try some spelling variations:
petrov » peterov (Expand Search), petriov (Expand Search), petruov (Expand Search)
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petruoi » peteruoi (Expand Search), petriuoi (Expand Search), petruuoi (Expand Search)
petruui » peteruui (Expand Search), petriuui (Expand Search), petruuui (Expand Search)
petruuui » peteruuui (Expand Search), petriuuui (Expand Search), petruuuui (Expand Search)
petr » peter (Expand Search), petri (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 (peteruv OR ((petrov OR petriov) OR ((petruoi OR (petruui OR petruuui)) OR petr))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (peteruv OR ((petrov OR petriov) OR ((petruoi OR (petruui OR petruuui)) OR petr))) o.s.*".