United States. Patent Office. (1903). Classification bulletin of U.S. Patent Office for months of May-June 1903, containing classification of subjects of invention revised by Classification Division of U.S. Patent Office. GPO.
Chicago Style (17th ed.) CitationUnited States. Patent Office. Classification Bulletin of U.S. Patent Office for Months of May-June 1903, Containing Classification of Subjects of Invention Revised by Classification Division of U.S. Patent Office. [Washington]: GPO, 1903.
MLA (9th ed.) CitationUnited States. Patent Office. Classification Bulletin of U.S. Patent Office for Months of May-June 1903, Containing Classification of Subjects of Invention Revised by Classification Division of U.S. Patent Office. GPO, 1903.
Warning: These citations may not always be 100% accurate.