Perhaps you should try some spelling variations:
petriv » petris (Expand Search), petrov (Expand Search), peteriv (Expand Search), petruiv (Expand Search), petroiv (Expand Search)
petruo » petru (Expand Search), petro (Expand Search), peteruo (Expand Search), petruuo (Expand Search), petrouo (Expand Search)
peteru » peter (Expand Search), petru (Expand Search), peters (Expand Search)
peteruo » petero (Expand Search), petruo (Expand Search), peterso (Expand Search)
petriuv » peteriuv (Expand Search), petruiuv (Expand Search), petroiuv (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 ((petriv OR petriuv) OR (((petruo OR peteru) OR peteruo) OR (petr OR petri))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriv OR petriuv) OR (((petruo OR peteru) OR peteruo) OR (petr OR petri))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriv OR petriuv) OR (((petruo OR peteru) OR peteruo) OR (petr OR petri))) o.s.*.