Greetings and Salutations:

These documents were found out on the "Interwebs". It is a matter of knowing that they exist to find them.

Look for (for example) "Space Shuttle" and "Flight Procedures". Good stuff.

A HUGE repository is at:
https://ntrs.nasa.gov/

Example:
https://ntrs.nasa.gov/search.jsp?N=0&Ntk=All&Ntt=%22Space%20Shuttle%22&Ntx=mode matchallpartial

Or random places:
https://sourceforge.net/projects/shuttleultra/files/References/

Your Mileage May Vary. Enjoy.