Perhaps you should try some spelling variations:
petrw » petrow (Expand Search), petre (Expand Search), peterw (Expand Search), perw (Expand Search)
petra » petre (Expand Search), petera (Expand Search), pera (Expand Search)
petru » pentru (Expand Search), peteru (Expand Search), peru (Expand Search)
petruow » pentruow (Expand Search), petrow (Expand Search), peteruow (Expand Search), peruow (Expand Search)
petro » petrov (Expand Search), petero (Expand Search), pero (Expand Search)
petr » peter (Expand Search), per (Expand Search)
petri » peteri (Expand Search), peri (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 (((((petrw OR petra) OR petru) OR (petruow OR petro)) o) OR ((petr OR petri) _)). s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((((petrw OR petra) OR petru) OR (petruow OR petro)) o) OR ((petr OR petri) _)). s.".
• Adding a wildcard symbol may retrieve word variants: fop (((((petrw OR petra) OR petru) OR (petruow OR petro)) o) OR ((petr OR petri) _)). s.*.