Perhaps you should try some spelling variations:
petriu » petri (Expand Search), petru (Expand Search), petriiu (Expand Search), petruiu (Expand Search), petroiu (Expand Search)
petris » petri (Expand Search), petriis (Expand Search), petruis (Expand Search), petrois (Expand Search)
petruo » petru (Expand Search), petro (Expand Search), petriuo (Expand Search), petruuo (Expand Search), petrouo (Expand Search)
petrooio » petriooio (Expand Search), petruooio (Expand Search), petroooio (Expand Search)
petrouuo » petriouuo (Expand Search), petruouuo (Expand Search), petroouuo (Expand Search)
petr » petri (Expand Search), petru (Expand Search), petro (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 ((petriu OR petris) OR (((petruo OR petrooio) OR petrouuo) OR ((petr OR per) OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriu OR petris) OR (((petruo OR petrooio) OR petrouuo) OR ((petr OR per) OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriu OR petris) OR (((petruo OR petrooio) OR petrouuo) OR ((petr OR per) OR peter))) o.s.*.