Back in ‘77, I used a Bio I text that my mother had used decades before. The only thing that had changed was the pictures had been colorized.
The Fluid Dynamics textbook that our Mechanical Engineering department had us buying was awkward at best, so when I was solving problems from it, I would submit them to the professor, solved with references to equations in my old man’s Fluid Dynamics engineering text. Oh BOY did that piss off the professor... who happened to be my advisor and Mechanical Engineering Dept. head.