Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), petriiov (Expand Search), petroiov (Expand Search), periov (Expand Search)
petruov » petrov (Expand Search), petriuov (Expand Search), petrouov (Expand Search), peruov (Expand Search), pentruov (Expand Search), petriov (Expand Search)
petroio » petrioio (Expand Search), petrooio (Expand Search), peroio (Expand Search)
petr » petri (Expand Search), petro (Expand Search), per (Expand Search)
petru » petriu (Expand Search), petrou (Expand Search), peru (Expand Search), pentru (Expand Search), petri (Expand Search)
peteri » peterdi (Expand Search), petri (Expand Search), peters (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 (petruov OR perouov)) OR (petroio OR (petr OR (petru OR (peteri OR peter))))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriov OR (petruov OR perouov)) OR (petroio OR (petr OR (petru OR (peteri OR peter))))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriov OR (petruov OR perouov)) OR (petroio OR (petr OR (petru OR (peteri OR peter))))) o.s.*.