Not technically survival stuff, and there are certainly newer versions of most of these PDFs, but some of you might find a nugget or two you hadn't seen elsewhere:
While the parent directory revolves around a particular medical issue, i thought there were some items listed here that might have some general medical interest:
This link went out on one of the prepper boards. Including it here for the folks who might have a reason to use one of the firearms-related calculators:
Surf around the parent directory, but between the JPG collection and the survival books, I found these two links to be the most useful portions of the site:
Spreadsheets for every imaginable thing. You might want to poke around the parent directory as well. Obviously there is a focus here on agriculture, but see if anything else interests you:
Most of this sites stuff is repetitive, but since many of these sites seem to drop off the net without warning, it doesn't hurt to have a backup site with similar material on it: