Perhaps you should try some spelling variations:
petriv » petrov (Expand Search), peteriv (Expand Search), petruiv (Expand Search), petroiv (Expand Search)
petris » peteris (Expand Search), petruis (Expand Search), petrois (Expand Search)
petruiio » peteruiio (Expand Search), petruuiio (Expand Search), petrouiio (Expand Search)
petroiio » peteroiio (Expand Search), petruoiio (Expand Search), petrooiio (Expand Search)
petrooiio » peterooiio (Expand Search), petruooiio (Expand Search), petroooiio (Expand Search)
petr » peter (Expand Search), petru (Expand Search), petro (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (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 (petriv OR ((petris OR (petruiio OR (petroiio OR petrooiio))) OR (petr OR petri))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (petriv OR ((petris OR (petruiio OR (petroiio OR petrooiio))) OR (petr OR petri))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (petriv OR ((petris OR (petruiio OR (petroiio OR petrooiio))) OR (petr OR petri))) o.s.*.