Perhaps you should try some spelling variations:
petrw » petrow (Expand Search), petru (Expand Search), petro (Expand Search), petruw (Expand Search), perw (Expand Search)
peterw » peters (Expand Search)
petr » petru (Expand Search), petro (Expand Search), per (Expand Search)
petri » petrui (Expand Search), petroi (Expand Search), peri (Expand Search)
petriov » petruiov (Expand Search), petroiov (Expand Search), periov (Expand Search), petrov (Expand Search)
petruuv » petruuuv (Expand Search), petrouuv (Expand Search), peruuv (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 ((((petrw OR peterw) OR (petr OR petri)) o) OR ((peter OR (petriov OR petruuv)) _)). s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petrw OR peterw) OR (petr OR petri)) o) OR ((peter OR (petriov OR petruuv)) _)). s.".
• Adding a wildcard symbol may retrieve word variants: fop ((((petrw OR peterw) OR (petr OR petri)) o) OR ((peter OR (petriov OR petruuv)) _)). s.*.