APA (7th ed.) Citation

United States. Patent Office. (1902). Classification bulletin of U.S. Patent Office for months of May and June 1902, containing classification of subjects of invention revised by Classification Division of U.S. Patent Office. GPO.

Chicago Style (17th ed.) Citation

United States. Patent Office. Classification Bulletin of U.S. Patent Office for Months of May and June 1902, Containing Classification of Subjects of Invention Revised by Classification Division of U.S. Patent Office. [Washington]: GPO, 1902.

MLA (9th ed.) Citation

United States. Patent Office. Classification Bulletin of U.S. Patent Office for Months of May and June 1902, Containing Classification of Subjects of Invention Revised by Classification Division of U.S. Patent Office. GPO, 1902.