Perhaps you should try some spelling variations:
petruo » petru (Expand Search), petro (Expand Search), petruuo (Expand Search), petrouo (Expand Search), peruo (Expand Search)
peters » petersen (Expand Search)
petris » petruis (Expand Search), petrois (Expand Search), peris (Expand Search)
petruuis » petruuuis (Expand Search), petrouuis (Expand Search), peruuis (Expand Search)
petrouo » petruouo (Expand Search), petroouo (Expand Search), perouo (Expand Search)
petr » petru (Expand Search), petro (Expand Search), per (Expand Search)
petri » petrui (Expand Search), petroi (Expand Search), peri (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 ((petris OR petruuis) OR (((petruo OR petrouo) OR (peters OR peter)) OR (petr OR petri))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petris OR petruuis) OR (((petruo OR petrouo) OR (peters OR peter)) OR (petr OR petri))) o.s.*".