Perhaps you should try some spelling variations:
perv » per (Expand Search)
peri » petri (Expand Search), per (Expand Search)
petrou » peterou (Expand Search), petriou (Expand Search), petruou (Expand Search)
petriiu » peteriiu (Expand Search), petriiiu (Expand Search), petruiiu (Expand Search)
petrui » peterui (Expand Search), petriui (Expand Search), petruui (Expand Search)
petrouui » peterouui (Expand Search), petriouui (Expand Search), petruouui (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 ((peteriv OR perv) OR ((((petrou OR petriiu) OR peri) OR (petrui OR petrouui)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((peteriv OR perv) OR ((((petrou OR petriiu) OR peri) OR (petrui OR petrouui)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((peteriv OR perv) OR ((((petrou OR petriiu) OR peri) OR (petrui OR petrouui)) OR petr)) o.s.*.