what references does mr birling make in his dinner speech

Birling’s speech is important, he argues, because the (left-leaning) intellectuals, “these Bernard Shaws and H.G. Wellses,” can’t be allowed to “do all the talking. We hard-headed practical business men must say something sometime.” As Birling finishes, Sybil and Sheila leave for the drawing room—and, presumably for a ticking down for his manners, she summons Eric, too.