Perhaps you should try some spelling variations:
peterov » petrov (Expand Search)
petrui » petri (Expand Search), pentrui (Expand Search), petrii (Expand Search), petriui (Expand Search), petroui (Expand Search), perui (Expand Search)
petrii » petri (Expand Search), petris (Expand Search), petriii (Expand Search), petroii (Expand Search), perii (Expand Search)
petriii » petrii (Expand Search), petrisi (Expand Search), petriiii (Expand Search), petroiii (Expand Search), periii (Expand Search)
petru » pentru (Expand Search), petri (Expand Search), petriu (Expand Search), petrou (Expand Search), peru (Expand Search)
petr » petri (Expand Search), petro (Expand Search), per (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 peterov) OR (((petrui OR (petrii OR petriii)) OR petru) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((peteriv OR peterov) OR (((petrui OR (petrii OR petriii)) OR petru) OR (petr OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((peteriv OR peterov) OR (((petrui OR (petrii OR petriii)) OR petru) OR (petr OR peter))) o.s.*.