Perhaps you should try some spelling variations:
petrov » petro (Expand Search), petriov (Expand Search), petruov (Expand Search), petroov (Expand Search)
petriiv » petriiiv (Expand Search), petruiiv (Expand Search), petroiiv (Expand Search)
petruuuiv » petriuuuiv (Expand Search), petruuuuiv (Expand Search), petrouuuiv (Expand Search)
petriov » petriiov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
petruov » petriuov (Expand Search), petruuov (Expand Search), petrouov (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 ((petriiv OR petruuuiv) OR ((petriov OR (petrov OR petruov)) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriiv OR petruuuiv) OR ((petriov OR (petrov OR petruov)) OR (petr OR peter))) o.s.*".