Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), peteriov (Expand Search), petriiov (Expand Search), petroiov (Expand Search)
petroov » petrov (Expand Search), peteroov (Expand Search), petrioov (Expand Search), petrooov (Expand Search)
peteri » peterdi (Expand Search), peter (Expand Search), petri (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petro (Expand Search)
petru » peteru (Expand Search), petriu (Expand Search), petrou (Expand Search), petri (Expand Search)
petris » peteris (Expand Search), petriis (Expand Search), petrois (Expand Search), petri (Expand Search)
petroiu » peteroiu (Expand Search), petrioiu (Expand Search), petrooiu (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 ((petriov OR petroov) OR (peteri OR (petr OR ((petru OR (petris OR petroiu)) OR pentru)))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriov OR petroov) OR (peteri OR (petr OR ((petru OR (petris OR petroiu)) OR pentru)))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriov OR petroov) OR (peteri OR (petr OR ((petru OR (petris OR petroiu)) OR pentru)))) o.s.*.