Perhaps you should try some spelling variations:
petra » petri (Expand Search), petru (Expand Search), petro (Expand Search), petria (Expand Search), petrua (Expand Search), petroa (Expand Search)
peterv » peters (Expand Search)
petrov » petro (Expand Search), petriov (Expand Search), petruov (Expand Search), petroov (Expand Search)
petrou » petru (Expand Search), petro (Expand Search), petrow (Expand Search), petriou (Expand Search), petruou (Expand Search), petroou (Expand Search)
petriiov » petriiiov (Expand Search), petruiiov (Expand Search), petroiiov (Expand Search)
petr » petri (Expand Search), petru (Expand Search), petro (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 ((petra OR peterv) OR ((petrov OR petriiov) OR ((petrou OR per) OR (petr OR peter)))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petra OR peterv) OR ((petrov OR petriiov) OR ((petrou OR per) OR (petr OR peter)))) o.s.*".