Perhaps you should try some spelling variations:
petroi » petri (Expand Search), petro (Expand Search), petrov (Expand Search)
petroiu » petriu (Expand Search), petrou (Expand Search), petrovu (Expand Search)
petrie » petri (Expand Search), petris (Expand Search), patrie (Expand Search)
petru » pentru (Expand Search), petri (Expand Search)
petrou » petro (Expand Search), petrov (Expand Search), petrow (Expand Search)
petriu » petri (Expand Search), petris (Expand Search)
per » petr (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 ((petroi OR petrie) OR (((petru OR petrou) OR (petriu OR petroiu)) OR (per OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petroi OR petrie) OR (((petru OR petrou) OR (petriu OR petroiu)) OR (per OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petroi OR petrie) OR (((petru OR petrou) OR (petriu OR petroiu)) OR (per OR peter))) o.s.*.