A couple of inside references in Frank Tashlin’s Porky the Fireman. The cartoon plugs its own series in one shot.
And in another scene, you can find references to director Friz Freleng and writer Tubby Millar (he wrote this particular cartoon).
Elmer Plummer? Griff Jay? I’m not sure who’s responsible for the backgrounds in the later ‘30s black-and-white Warners cartoons.
J.S. Zamecnik’s “Traffic” is featured prominently through the cartoon, including the opening scenes involving the fire truck.