Perhaps you should try some spelling variations:
petrv » petrov (Expand Search), petru (Expand Search), petro (Expand Search), peterv (Expand Search), petruv (Expand Search)
petruv » petru (Expand Search), petrov (Expand Search), peteruv (Expand Search), petruuv (Expand Search), petrouv (Expand Search)
peterv » peter (Expand Search), peters (Expand Search)
petr » peter (Expand Search), petru (Expand Search), petro (Expand Search)
petrui » peterui (Expand Search), petruui (Expand Search), petroui (Expand Search), petru (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 (((petrv OR petruv) OR peterv) OR (petr OR (petrui OR petri))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petrv OR petruv) OR peterv) OR (petr OR (petrui OR petri))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petrv OR petruv) OR peterv) OR (petr OR (petrui OR petri))) o.s.*.