Perhaps you should try some spelling variations:
petroov » petrov (Expand Search), petruoov (Expand Search), petrooov (Expand Search), peroov (Expand Search)
petriv » petris (Expand Search), petrov (Expand Search), petruiv (Expand Search), petroiv (Expand Search), periv (Expand Search)
petriu » petru (Expand Search), petris (Expand Search), petruiu (Expand Search), petroiu (Expand Search), periu (Expand Search)
petriuo » petruo (Expand Search), petriso (Expand Search), petruiuo (Expand Search), petroiuo (Expand Search), periuo (Expand Search)
petr » petru (Expand Search), petro (Expand Search), per (Expand Search)
petri » petrui (Expand Search), petroi (Expand Search), peri (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 ((petroov OR petriv) OR ((petriu OR petriuo) OR ((petr OR petri) OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petroov OR petriv) OR ((petriu OR petriuo) OR ((petr OR petri) OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petroov OR petriv) OR ((petriu OR petriuo) OR ((petr OR petri) OR peter))) o.s.*.