The US Federal code of regulations. Im a US customs broker. At 50 titles and sometimes 100s of pages per title if not thousands, it’d be quite the read in one go!
Edit: I just checked, it changes pretty regularly, usually stands somewhere around 90 thousand pages.
The specific code on customs brokers is title 19 part 111. But really the whole thing is specific to my job in one way or another. I’ve never actually read the entire thing personally as it’s practically impossible. I look up whatever I need to as needed.
As someone going into conservation I'd probably just throw a copy Nat Geo at them or something. If we were talking about shows/movies I'd go with Wildcat, even if it is a depressing documentary.
It’s a book that takes the theory out of acoustic design and loudspeaker placement / management, and says “Life sucks, it’s never perfect, let’s make it suck less.”