section-6-welcome-message
section-6-reading-notes
datatype-programming-in-racket-without-structs
datatype-programming-in-racket-with-structs
advantages-of-structs
implementing-programming-languages
what-your-interpreter-can-and-cannot-assume
implementing-variables-and-environments
implementing-closures
optional-are-closures-efficient
racket-functions-as-macros-for-interpreted-language