Perhaps you should try some spelling variations:
petr » peter (Expand Search), petru (Expand Search), petro (Expand Search)
petrov » peterov (Expand Search), petruov (Expand Search), petroov (Expand Search), petro (Expand Search)
petrou » peterou (Expand Search), petruou (Expand Search), petroou (Expand Search), petru (Expand Search), petro (Expand Search), petrow (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petriov » peteriov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
petruov » peteruov (Expand Search), petruuov (Expand Search), petrouov (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 (((petrov OR (petrou OR petri)) OR (petriov OR peteriov)) OR petruov)) _. s.~".
• Adding a wildcard symbol may retrieve word variants: fop (petr OR (((petrov OR (petrou OR petri)) OR (petriov OR peteriov)) OR petruov)) _. s.*.