Perhaps you should try some spelling variations:
petroiv » petrov (Expand Search), petrioiv (Expand Search), petruoiv (Expand Search), petrooiv (Expand Search)
petris » petri (Expand Search), petriis (Expand Search), petruis (Expand Search), petrois (Expand Search)
petruov » petrov (Expand Search), petriuov (Expand Search), petruuov (Expand Search), petrouov (Expand Search)
petriis » petriiis (Expand Search), petruiis (Expand Search), petroiis (Expand Search)
petriiois » petriiiois (Expand Search), petruiiois (Expand Search), petroiiois (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 ((petroiv OR ((petris OR petriis) OR petriiois)) OR (petruov OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petroiv OR ((petris OR petriis) OR petriiois)) OR (petruov OR (petr OR peter))) o.s.*".