Perhaps you should try some spelling variations:
petr » peter (Expand Search), petru (Expand Search), petro (Expand Search)
petruo » peteruo (Expand Search), petruuo (Expand Search), petrouo (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)
petruui » peteruui (Expand Search), petruuui (Expand Search), petrouui (Expand Search)
pero » petro (Expand Search), per (Expand Search), pro (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 (((peruw OR (petr OR petruo)) o) OR (((pero OR petri) OR (petroi OR petruui)) _)). s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((peruw OR (petr OR petruo)) o) OR (((pero OR petri) OR (petroi OR petruui)) _)). s.".
• Adding a wildcard symbol may retrieve word variants: fop (((peruw OR (petr OR petruo)) o) OR (((pero OR petri) OR (petroi OR petruui)) _)). s.*.