Download links for DFARS 252.204-7012 resources:
Official DFARS guidance: https://www.acq.osd.mil/dpap/dars/dfars/html/current/204_73.htm
NIST page about DFARS for manufacturers: https://www.nist.gov/mep/cybersecurity-resources-manufacturers/dfars-compliance
NIST self-assessment handbook for using SP 800-171 controls for DFARS requirements: http://nvlpubs.nist.gov/nistpubs/hb/2017/NIST.HB.162.pdf
If you know of other official or helpful resources, please comment to help others! I’ll add the links to this page.