A peer in the underground comics field, Victor Moscoso, commented about his first impression of Crumb's work, in the mid-1960s, before meeting Crumb in person: "I couldn't tell if it was an old man drawing young, or a young man drawing old." Robert Crumb's cartooning style has drawn on the work of cartoon artists from earlier generations, including Billy DeBeck (Barney Google), C. E. Brock (an old story book illustrator), Gene Ahern's comic strips, Basil Wolverton (Powerhouse Pepper), George Baker (Sad Sack), Ub Iwerks's characters for animation, Isadore Freleng's drawings for the early Merrie Melodies and Looney Tunes of the 1930s, Sidney Smith (The Gumps), Rube Goldberg, E. C. Segar (Popeye) and Bud Fisher (Mutt and Jeff). Crumb has cited Carl Barks, who illustrated Disney's "Donald Duck" comic books and John Stanley (Little Lulu) as formative influences on his narrative approach, as well as Harvey Kurtzman of Mad Magazine fame.