Chicago
Reports of cases argued and adjudged in the Supreme Court of the United States, February term, 1821, https://www.govinfo.gov/app/details/USREPORTS-19.
APA
Reports of cases argued and adjudged in the Supreme Court of the United States, February term, 1821 https://www.govinfo.gov/app/details/USREPORTS-19.
MLA
Reports of cases argued and adjudged in the Supreme Court of the United States, February term, 1821. https://www.govinfo.gov/app/details/USREPORTS-19.
Bluebook
Reports of cases argued and adjudged in the Supreme Court of the United States, February term, 1821.