Perhaps you should try some spelling variations:
petrois » petris (Expand Search), peterois (Expand Search), petruois (Expand Search), petroois (Expand Search)
petruo » petru (Expand Search), petro (Expand Search), peteruo (Expand Search), petruuo (Expand Search), petrouo (Expand Search)
peteri » peterdi (Expand Search), peter (Expand Search), peters (Expand Search)
petruiio » peteruiio (Expand Search), petruuiio (Expand Search), petrouiio (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 (petrois OR (((petruo OR peteri) OR petruiio) OR (petr OR (petri OR peteri)))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (petrois OR (((petruo OR peteri) OR petruiio) OR (petr OR (petri OR peteri)))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (petrois OR (((petruo OR peteri) OR petruiio) OR (petr OR (petri OR peteri)))) o.s.*.