Perhaps you should try some spelling variations:
petrio » petro (Expand Search), peterio (Expand Search), petroio (Expand Search), perio (Expand Search)
petruiv » pentruiv (Expand Search), peteruiv (Expand Search), petrouiv (Expand Search), peruiv (Expand Search)
petruio » pentruio (Expand Search), peteruio (Expand Search), petrouio (Expand Search), peruio (Expand Search)
petru » pentru (Expand Search), peteru (Expand Search), petrou (Expand Search), peru (Expand Search)
petris » peteris (Expand Search), petrois (Expand Search), peris (Expand Search)
petr » peter (Expand Search), petro (Expand Search), per (Expand Search)
petri » peteri (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 ((petris OR petruiv) OR (((petrio OR petruio) OR (petru OR peruuo)) OR (petr OR petri))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petris OR petruiv) OR (((petrio OR petruio) OR (petru OR peruuo)) OR (petr OR petri))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petris OR petruiv) OR (((petrio OR petruio) OR (petru OR peruuo)) OR (petr OR petri))) o.s.*.