Facebook ads

Is there a trick or just a good resource you recommend to finding similar brands to market to their audiences on Facebook when driving cold traffic? I’ve found several pages/brands I’d like to create audiences around, but Facebook is not recognizing them when I’m creating my ads and I’m getting really frustrated. Is there a trick to getting Facebook to recognize a page under “interests,” or is it just a crap shoot and you have to have a whole bunch of pages your ideal client might also be interested in to try until you find one Facebook recognizes?