This came up in another thread recently, here’s the latest from Aaron: Is it common for IF authors to use a standard library they have accumulated from their own and other's source code? - #34 by aaronius
Zed Lopez has a couple of possible leads on getting a reasonably-priced copy of the current edition later in that thread: Is it common for IF authors to use a standard library they have accumulated from their own and other's source code? - #37 by Zed