Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), petruiov (Expand Search), petroiov (Expand Search), periov (Expand Search)
petruio » petruo (Expand Search), petruuio (Expand Search), petrouio (Expand Search), peruio (Expand Search)
petrui » petru (Expand Search), petruui (Expand Search), petroui (Expand Search), perui (Expand Search)
petruo » petru (Expand Search), petro (Expand Search), petruuo (Expand Search), petrouo (Expand Search), peruo (Expand Search)
petri » petrui (Expand Search), petroi (Expand Search), peri (Expand Search)
petris » petruis (Expand Search), petrois (Expand Search), peris (Expand Search)
petr » petru (Expand Search), petro (Expand Search), per (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 (((petri OR ((petruio OR petris) OR petrui)) OR petruo) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (petriov OR (((petri OR ((petruio OR petris) OR petrui)) OR petruo) OR (petr OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (petriov OR (((petri OR ((petruio OR petris) OR petrui)) OR petruo) OR (petr OR peter))) o.s.*.