Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), petriiov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
peterov » petrov (Expand Search)
petriuiv » petriiuiv (Expand Search), petruiuiv (Expand Search), petroiuiv (Expand Search)
petriiuiv » petriiiuiv (Expand Search), petruiiuiv (Expand Search), petroiiuiv (Expand Search)
petriio » petriiio (Expand Search), petruiio (Expand Search), petroiio (Expand Search)
petr » petri (Expand Search), petru (Expand Search), petro (Expand Search)

Try widening your search to All Fields.

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 peterov) OR (petriuiv OR petriiuiv)) OR (petriio OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petriov OR peterov) OR (petriuiv OR petriiuiv)) OR (petriio OR (petr OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petriov OR peterov) OR (petriuiv OR petriiuiv)) OR (petriio OR (petr OR peter))) o.s.*.