Perhaps you should try some spelling variations:
petriiov » petrov (Expand Search), peteriiov (Expand Search), petriiiov (Expand Search), petruiiov (Expand Search)
peteroov » petrov (Expand Search)
petriuov » petrov (Expand Search), peteriuov (Expand Search), petriiuov (Expand Search), petruiuov (Expand Search)
petrou » peterou (Expand Search), petriou (Expand Search), petruou (Expand Search)
petriou » peteriou (Expand Search), petriiou (Expand Search), petruiou (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 (((petriiov OR peteroov) OR petriuov) OR ((petrou OR (petrou OR petriou)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petriiov OR peteroov) OR petriuov) OR ((petrou OR (petrou OR petriou)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petriiov OR peteroov) OR petriuov) OR ((petrou OR (petrou OR petriou)) OR petr)) o.s.*.