Perhaps you should try some spelling variations:
peterov » peterv (Expand Search), petersv (Expand Search), petrov (Expand Search)
petero » peter (Expand Search), peters (Expand Search), petro (Expand Search)
petrov » petro (Expand Search), peterov (Expand Search), petruov (Expand Search), petroov (Expand Search)
petroio » peteroio (Expand Search), petruoio (Expand Search), petrooio (Expand Search)
petr » peter (Expand Search), petru (Expand Search), petro (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (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 ((peterov OR peteriuv) OR ((petero OR petroio) OR ((petrov OR petr) OR petri))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((peterov OR peteriuv) OR ((petero OR petroio) OR ((petrov OR petr) OR petri))) o.s.*".