Perhaps you should try some spelling variations:
petrois » petris (Expand Search), peterois (Expand Search), petroois (Expand Search)
petra » petro (Expand Search), petera (Expand Search), petroa (Expand Search)
petre » petro (Expand Search), petere (Expand Search), petroe (Expand Search)
petere » peter (Expand Search), peters (Expand Search), petersen (Expand Search)
petr » peter (Expand Search), petro (Expand Search)
petru » peteru (Expand Search), petrou (Expand Search), pentru (Expand Search)
petri » peteri (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 ((petra OR (petre OR petere)) OR (petr OR per))) OR (petru OR petri)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petrois OR ((petra OR (petre OR petere)) OR (petr OR per))) OR (petru OR petri)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petrois OR ((petra OR (petre OR petere)) OR (petr OR per))) OR (petru OR petri)) o.s.*.