Perhaps you should try some spelling variations:
petrois » petris (Expand Search), petruois (Expand Search), petroois (Expand Search)
petrou » petru (Expand Search), petro (Expand Search), petrov (Expand Search), petruou (Expand Search), petroou (Expand Search)
petriu » petru (Expand Search), petris (Expand Search), petruiu (Expand Search), petroiu (Expand Search)
petrovvis » petruovvis (Expand Search), petroovvis (Expand Search)
petr » petru (Expand Search), petro (Expand Search)
petri » petrui (Expand Search), petroi (Expand Search)

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: fop ((petrois OR petrovvis) OR ((petrou OR petriu) OR (((petr OR petri) OR per) OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petrois OR petrovvis) OR ((petrou OR petriu) OR (((petr OR petri) OR per) OR peter))) o.s.*".