(EN) Brian D'Ambrosio, From Football to Fig Newtons: 76 American Inventors and The Inventions You Know By Heart, Lulu.com, p. 61, ISBN 9781105737725. URL consultato il 18 febbraio 2019.
«William Kitchiner's The Cook's Oracle includes a recipe for what can only be described as a potato chip. Whether one called it a potato chip or not, it would seem that a thinly sliced potato cooked in hot oil and served sprinkled with salt existed before George Speck or his sister Katie Speck Wicks "invented" the potato chip.»