Perhaps you should try some spelling variations:
petrov » petro (Expand Search), peterov (Expand Search), petruov (Expand Search), petroov (Expand Search)
petero » peter (Expand Search), peters (Expand Search), petro (Expand Search)
petroiov » peteroiov (Expand Search), petruoiov (Expand Search), petrooiov (Expand Search)
petriioi » peteriioi (Expand Search), petruiioi (Expand Search), petroiioi (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petr » peter (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 ((petroiov OR petrov) OR (((petriioi OR (petri OR petri)) OR petero) OR (petr OR per))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petroiov OR petrov) OR (((petriioi OR (petri OR petri)) OR petero) OR (petr OR per))) o.s.*".