Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), petriiov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
petruo » petru (Expand Search), petro (Expand Search), petriuo (Expand Search), petruuo (Expand Search), petrouo (Expand Search)
petruuuo » petriuuuo (Expand Search), petruuuuo (Expand Search), petrouuuo (Expand Search)
petruiiio » petriuiiio (Expand Search), petruuiiio (Expand Search), petrouiiio (Expand Search)
petruio » petriuio (Expand Search), petruuio (Expand Search), petrouio (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 (petriov OR (((petruo OR petruuuo) OR (petruiiio OR petruio)) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (petriov OR (((petruo OR petruuuo) OR (petruiiio OR petruio)) OR (petr OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (petriov OR (((petruo OR petruuuo) OR (petruiiio OR petruio)) OR (petr OR peter))) o.s.*.