Perhaps you should try some spelling variations:
petriow » petrow (Expand Search), peteriow (Expand Search), petriiow (Expand Search), petruiow (Expand Search)
petrou » petru (Expand Search), petro (Expand Search), petrov (Expand Search), peterou (Expand Search), petriou (Expand Search), petruou (Expand Search)
petroi » petri (Expand Search), petro (Expand Search), petrov (Expand Search), peteroi (Expand Search), petrioi (Expand Search), petruoi (Expand Search)
petrivw » peterivw (Expand Search), petriivw (Expand Search), petruivw (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (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 petrou) OR petrivw) o) OR ((petroi OR petr) _)). s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petriow OR petrou) OR petrivw) o) OR ((petroi OR petr) _)). s.".
• Adding a wildcard symbol may retrieve word variants: fop ((((petriow OR petrou) OR petrivw) o) OR ((petroi OR petr) _)). s.*.