Chicago
Memorandum
https://www.govinfo.gov/app/details/USREPORTS-21/USREPORTS-21-FrontMatter-5.
APA
Memorandum
https://www.govinfo.gov/app/details/USREPORTS-21/USREPORTS-21-FrontMatter-5.
MLA
Memorandum.
https://www.govinfo.gov/app/details/USREPORTS-21/USREPORTS-21-FrontMatter-5.
Bluebook
Memorandum.