
Before there were neural networks and image-hacking, there was the gritty math-hacking to optimize big gobs of interrelated stuff that had to happen in the right order. It was almost always done in Fortran, and I suspect a lot of it still is. (And if it was not done in Fortran, it was done in APL. Ask an Actuarial scientist, if you doubt this..) Please don't laugh at Fortran. It can not only help you fly your spaceship to another planet (and get you home again!), it can also make you (and your client) rich, since you can build solid, bulletproof code from those old libraries that just works, and hence create flaw-free solutions to really critically important applications. This proposed extension looks useful.
Optimization Techniques With Fortran by J. Kuester (1973-06-01) Paperback – January 1, 1656 by J. Kuester (Author)
The title, obviously, is "Optimization Techniques with Fortran". Fortran is old, but the book was not written in 1656. Unmentioned by Amazon, there is a coauthor, Joe H. Mize, according to Google books.
I guess the answers to my question are that bad information does not hurt sales if it still has the keywords that customers would search, especially for old, obscure books with low sales in any case.