Perhaps you should try some spelling variations:
petris » petri (Expand Search), peteris (Expand Search), petriis (Expand Search), petrois (Expand Search)
petru » pentru (Expand Search), petri (Expand Search), peteru (Expand Search), petriu (Expand Search), petrou (Expand Search)
petrov » petro (Expand Search), peterov (Expand Search), petriov (Expand Search), petroov (Expand Search)
petra » petri (Expand Search), petro (Expand Search), petre (Expand Search), petera (Expand Search), petria (Expand Search), petroa (Expand Search)
petriis » peteriis (Expand Search), petriiis (Expand Search), petroiis (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petro (Expand Search)
petriv » peteriv (Expand Search), petriiv (Expand Search), petroiv (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 ((((petris OR petriis) OR (petru OR petrov)) OR petra) OR (petr OR (petriv OR petra))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petris OR petriis) OR (petru OR petrov)) OR petra) OR (petr OR (petriv OR petra))) o.s.*".