In 1952, the first edition of his book, Theory of Numbers, was published.[4]
Stewart's contributions to number theory also include a complete characterization of the practical numbers in terms of their factorizations, which he published in 1954, a year before Wacław Sierpiński's independent discovery of the same result.
B. M. Stewart, Adventures Among the Toroids (1970) This 5"x13" edition was self-published by the author (printed by The John Henry Company) and has no ISBN.