Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), peteriov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
petero » peter (Expand Search), peters (Expand Search), petro (Expand Search)
petrio » petro (Expand Search), peterio (Expand Search), petruio (Expand Search), petroio (Expand Search)
petris » peteris (Expand Search), petruis (Expand Search), petrois (Expand Search)
petroio » peteroio (Expand Search), petruoio (Expand Search), petrooio (Expand Search)
petr » peter (Expand Search), petru (Expand Search), petro (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (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 petris) OR ((petero OR (petrio OR petroio)) OR (petr OR petri))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriov OR petris) OR ((petero OR (petrio OR petroio)) OR (petr OR petri))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriov OR petris) OR ((petero OR (petrio OR petroio)) OR (petr OR petri))) o.s.*.