Perhaps you should try some spelling variations:
petrw » petrow (Expand Search), petru (Expand Search), petra (Expand Search), peterw (Expand Search), petruw (Expand Search), perw (Expand Search)
petrouw » petrow (Expand Search), petrovuw (Expand Search), petruuw (Expand Search), peterouw (Expand Search), petruouw (Expand Search), perouw (Expand Search)
petro » petrov (Expand Search), petru (Expand Search), petero (Expand Search), petruo (Expand Search), pero (Expand Search)
petr » peter (Expand Search), petru (Expand Search), per (Expand Search)
petri » peteri (Expand Search), petrui (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 petrouw) OR petro) OR petro) o) OR ((petr OR petri) _)). s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((((petrw OR petrouw) OR petro) OR petro) o) OR ((petr OR petri) _)). s.".
• Adding a wildcard symbol may retrieve word variants: fop (((((petrw OR petrouw) OR petro) OR petro) o) OR ((petr OR petri) _)). s.*.