12.8 For further reading
The topics of this chapter are covered in every quantum mechanics textbook,
with a discussion providing more physical motivation. For a mathematics text-
book that covers distributional solutions of the Schr ̈odinger equation in detail,
see [72]. In the textbook [41] for mathematicians, see chapter 4 for a more
detailed mathematically rigorous treatment of the free particle, and chapter 12
for a careful treatment of the subtleties of Heisenberg uncertainty.