Perhaps you should try some spelling variations:
petr » peter (Expand Search), petru (Expand Search), petro (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petroi » peteroi (Expand Search), petruoi (Expand Search), petrooi (Expand Search), petro (Expand Search), petrov (Expand Search), petrow (Expand Search)
petroov » peteroov (Expand Search), petruoov (Expand Search), petrooov (Expand Search), petrov (Expand Search)
petruov » peteruov (Expand Search), petruuov (Expand Search), petrouov (Expand Search), petrov (Expand Search)

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petr OR (petri OR petroi)) OR (petroov OR petruov)) _. s.~".
• Adding a wildcard symbol may retrieve word variants: fop ((petr OR (petri OR petroi)) OR (petroov OR petruov)) _. s.*.