United States. Patent Office & ProQuest (Firm). (1821). Letter from the Secretary of State, transmitting a list of the names of persons to whom patents have been issued for any useful invention, during the year 1820. [publisher not identified].
Chicago Style (17th ed.) CitationUnited States. Patent Office and ProQuest (Firm). Letter from the Secretary of State, Transmitting a List of the Names of Persons to Whom Patents Have Been Issued for Any Useful Invention, During the Year 1820. Washington: [publisher not identified], 1821.
MLA (9th ed.) CitationUnited States. Patent Office and ProQuest (Firm). Letter from the Secretary of State, Transmitting a List of the Names of Persons to Whom Patents Have Been Issued for Any Useful Invention, During the Year 1820. [publisher not identified], 1821.