Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), petruiov (Expand Search), petroiov (Expand Search), periov (Expand Search)
petrou » petru (Expand Search), petro (Expand Search), petrov (Expand Search), petruou (Expand Search), petroou (Expand Search), perou (Expand Search)
petri » petrui (Expand Search), petroi (Expand Search), peri (Expand Search)
petriio » petruiio (Expand Search), petroiio (Expand Search), periio (Expand Search)
petroiio » petruoiio (Expand Search), petrooiio (Expand Search), peroiio (Expand Search)
petr » petru (Expand Search), petro (Expand Search), per (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 ((petriov OR periv) OR (((petri OR (petriio OR petroiio)) OR petrou) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriov OR periv) OR (((petri OR (petriio OR petroiio)) OR petrou) OR (petr OR peter))) o.s.*".