Tristan Donovan (November 1, 2013). Fizz: How Soda Shook Up the World. Chicago Review Press. pp. 72. ISBN978-1-61374-725-4. https://books.google.com/books?id=BTIFAQAAQBAJ&pg=PA72. "The cola part of the name was an obvious nod to the cola flavor of the drink, whil the word Pepsi referred to his goal of making an indigestion-easing beverage. Whether the wor Pepsi came from the digestive enzyme pepsin or dyspesia [...] or both isn't known."
