Chris Okasaki. Purely Functional Data Structures. Cambridge University Press. ISBN 978-051153-010-4. 1998.

Not a Lisp book per se, but a treatment of data structures from a functional programming perspective. The code examples are in Standard ML, but the ideas apply strongly to Lisp and Scheme. Definitely a useful source for an alternative take on data structuring that doesn’t start from assumptions of imperative programming and mutability.