Perhaps you should try some spelling variations:
peteruov » petrov (Expand Search)
petro » petrov (Expand Search), petri (Expand Search), petr (Expand Search)
peri » petri (Expand Search), per (Expand Search)
peru » per (Expand Search)
petruv » pentruv (Expand Search), petriv (Expand Search)
petrui » pentrui (Expand Search), petrii (Expand Search)
petruui » pentruui (Expand Search), petriui (Expand Search)
petru » pentru (Expand Search), petri (Expand Search)

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 peteruov) OR ((((petro OR petrui) OR (petruui OR peri)) OR peru) OR petru)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruv OR peteruov) OR ((((petro OR petrui) OR (petruui OR peri)) OR peru) OR petru)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruv OR peteruov) OR ((((petro OR petrui) OR (petruui OR peri)) OR peru) OR petru)) o.s.*.