I downloaded the PDF, don't waste your time. It is a poorly structured, poorly written, anonymous "book" that reads like paraphrased chunks of content cribbed from all over. It also contains affiliate links and adverts.
If you're interested in reading about the military and resilience, check out information from genuine sources instead.
Does it have to be military-related, or about resilience in general? Military-related:
There are few resources specific to the special forces that are actually any good (I could only find non-experts pushing an agenda with this concept).
So...who wrote this? Not to disparage self-publishing, but generally decent books have a writer and a methodology behind it.
I'm downloading it for free just to amuse myself, but if anyone here is genuinely interested in this subject, why not look for books by actual experts? It wouldn't surprise me if this is just stealing content from published materials.
EDIT: Yeah, it is terrible, don't waste your time. It is poorly structured, with no references, and reads like paraphrased chunks of content cribbed from all over. It also contains affiliate links and adverts. Imagine if you actually paid for a "book" of advertising?