Vodka searching. AKA Yandex.
Goog/Duckduckgo/and almost all others heavily filter.
Here is a Vodka search for Tropos white hats scribd
https://yandex.com/search/?text=tropos+white+hats+scribd&lr=102582
Great Vodka searches get great results.
Some things the white hats tried to make public and known ended up heavily filtered. And some of it has been there a long time.
Knowing this, things you have tried to find in the past and ended up finding nothing, try again with yandex.
Save your results locally or use an encrypted email service, make your account very secure, send the files to yourself.
Your email login and password should be so secure that you have to write it down (not type it, no digital password storage).