Perhaps you should try some spelling variations:
"fop perov OR petriiv OR peroov OR petru OR petero OR peri OR pero OR petr o.s.*" » "fop petrov OR petriiv OR peroov OR petru OR petero OR peri OR pero OR petr o.s.*" (Expand Search), "fop perov OR petriiv OR peroov OR petru OR petero OR petri OR pero OR petr o.s.*" (Expand Search), "fop perov OR petriiv OR peroov OR petru OR petero OR per OR pero OR petr o.s.*" (Expand Search), "fop perov OR peteriiv OR peroov OR peteru OR petero OR peri OR pero OR peter o.s.*" (Expand Search), "fop perov OR petriiiv OR peroov OR petriu OR petero OR peri OR pero OR petri o.s.*" (Expand Search), "fop perov OR petroiiv OR peroov OR petrou OR petero OR peri OR pero OR petro o.s.*" (Expand Search)

You may be able to get more results by adjusting your search query.

• Removing quotes may allow a broader search: fop (((perov OR petriiv) OR peroov) OR (petru OR (((petero OR peri) OR pero) OR petr))) o.s.*.