Perhaps you should try some spelling variations:
pero » petro (Expand Search), per (Expand Search), pro (Expand Search)
petroov » petrov (Expand Search), petruoov (Expand Search), petrooov (Expand Search), peroov (Expand Search)
petris » petruis (Expand Search), petrois (Expand Search), peris (Expand Search)
petruou » petruuou (Expand Search), petrouou (Expand Search), peruou (Expand Search)
petri » petrui (Expand Search), petroi (Expand Search), peri (Expand Search)
petr » petru (Expand Search), petro (Expand Search), per (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 ((petris OR (pero OR petroov)) OR ((petruou OR (petri OR peruoi)) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petris OR (pero OR petroov)) OR ((petruou OR (petri OR peruoi)) OR (petr OR peter))) o.s.*".