I'm still working on generating the MATH eBook, but the 3-in-1 book (MATH+MECH+CALC) is available here: https://gumroad.com/l/noBSmath Chapter 1 of the 3-in-1 book is essentially the same as the No Bullshit guide to Mathematics.

You can see a preview here: https://minireference.com/static/excerpts/noBSguide_v5_previ...

what is the difference between no bs guide to mathematics and the 3-in-1 book?

The 3-in-1 book contains a high school math review, a mechanics course, and a calculus course (450pp). The No bs guide to math is just the high school math review and is much thinner 170pp. (I'm essentially cutting up the 3-in-1 book and releasing it as split books because I realize 450pp can be intimidating for some readers).