Perhaps you should try some spelling variations:
peterov » petrov (Expand Search)
petris » petri (Expand Search), petriis (Expand Search), petruis (Expand Search), petrois (Expand Search)
petriou » petriiou (Expand Search), petruiou (Expand Search), petroiou (Expand Search)
petriuuo » petriiuuo (Expand Search), petruiuuo (Expand Search), petroiuuo (Expand Search)
petruiiuuo » petriuiiuuo (Expand Search), petruuiiuuo (Expand Search), petrouiiuuo (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 ((peterov OR petris) OR ((petriou OR (petriuuo OR petruiiuuo)) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((peterov OR petris) OR ((petriou OR (petriuuo OR petruiiuuo)) OR (petr OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((peterov OR petris) OR ((petriou OR (petriuuo OR petruiiuuo)) OR (petr OR peter))) o.s.*.