Marx Brothers appeared, sometimes with Chico and Zeppo caricatured, in cartoons starring Mickey Mouse, Flip the Frog and others. In the "Airwolf" episode 'Condemned', four anti-virus formulae for a deadly plague were named after the four Marx Brothers. In "All in the Family", Rob Reiner often did imitations of Groucho, and Sally Struthers dressed as Harpo in one episode in which she (as Gloria Stivic) and Rob (as Mike Stivic) were going to a Marx Brothers film festival, with Reiner dressing as Groucho. Gabe Kaplan did many Groucho imitations on his sit-com "Welcome Back, Kotter" and Robert Hegyes sometimes imitated both Chico
Karl Marx and the Close of His System has been seen as one of the most important discussions of Marx's economic theories, along with Rudolf Hilferding's "Böhm-Bawerk's Criticism of Marx", a defense of Marx against Bawerk. Bawerk's work is the "classical" critique of "Capital". Most subsequent critiques of Marxist economics have repeated Bawerk's arguments. Marxist economist Ernest Mandel identifies "Karl Marx and the Close of His System" as part of a literature, beginning with German social democrat Eduard Bernstein, that criticizes the dialectical method Marx borrowed from Georg Wilhelm Friedrich Hegel as "useless", "metaphysical", or "mystifying." He faults Böhm-Bawerk and the other critics for what he regards as