Even actuallier, the first book was titled "The World of Ā" but "to reduce printing costs, the 1953 and 1964 Ace Books paperback editions were entitled The Worl

Even actuallier, the first book was titled "The World of Ā" but "to reduce printing costs, the 1953 and 1964 Ace Books paperback editions were entitled The World of Null-A, and the symbol Ā was replaced with "null-A" throughout the text." [1] [1] https://en.wikipedia.org/wiki/The_World_of_Null-A#Publication_history https://en.wikipedia.org/wiki/The_World_of_Null-A#Publicatio...