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