Another US Government shutdown may start this Friday (February 15th), if you do not have the NIST documents you need for your studying remember to download them before Friday.
I would recommend getting at least NIST 800-37 and NIST 800-53, follow the links below and click “Local Download”
https://csrc.nist.gov/publications/detail/sp/800-37/rev-2/final
https://csrc.nist.gov/publications/detail/sp/800-53/rev-4/final