Perhaps you should try some spelling variations:
petriow » petrow (Expand Search), peteriow (Expand Search), petriiow (Expand Search), petruiow (Expand Search)
petruw » petru (Expand Search), petrow (Expand Search), peteruw (Expand Search), petriuw (Expand Search), petruuw (Expand Search)
petruuw » peteruuw (Expand Search), petriuuw (Expand Search), petruuuw (Expand Search)
petrivw » peterivw (Expand Search), petriivw (Expand Search), petruivw (Expand Search)
petriivw » peteriivw (Expand Search), petriiivw (Expand Search), petruiivw (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (Expand Search)
petruov » peteruov (Expand Search), petriuov (Expand Search), petruuov (Expand Search), petrov (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 ((((petriow OR (petruw OR petruuw)) OR (petrivw OR petriivw)) o) OR ((petr OR petruov) _)). s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petriow OR (petruw OR petruuw)) OR (petrivw OR petriivw)) o) OR ((petr OR petruov) _)). s.".
• Adding a wildcard symbol may retrieve word variants: fop ((((petriow OR (petruw OR petruuw)) OR (petrivw OR petriivw)) o) OR ((petr OR petruov) _)). s.*.