There's an HTML, non-Scribd, version of the mentioned book (pamphlet?) by David Black here:
https://wn.rudolfsteinerelib.org/RelArtic/BlackDavid/DB1981/...
Seems the author does technical due diligence at a VC firm now:
https://www.blackliszt.com/2021/10/what-is-technical-due-dil...