Perhaps you should try some spelling variations:
petrov » petro (Expand Search), petruov (Expand Search), petroov (Expand Search), perov (Expand Search)
petra » petru (Expand Search), petro (Expand Search), petrua (Expand Search), petroa (Expand Search), pera (Expand Search)
petre » petru (Expand Search), petro (Expand Search), petrue (Expand Search), petroe (Expand Search), pere (Expand Search)
petriooi » petruiooi (Expand Search), petroiooi (Expand Search), periooi (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 ((petrov OR (petra OR petre)) OR (petriooi OR ((petr OR petri) OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petrov OR (petra OR petre)) OR (petriooi OR ((petr OR petri) OR peter))) o.s.*".