44 U.S.C. § 1718: Distribution of Government publications to the Library of Congress

There shall be printed and furnished to the Library of Congress for official use in the District of Columbia not to exceed twenty-five copies of: House documents and reports, bound; Senate documents and reports, bound; Senate and House journals, bound; public bills and resolutions; the United States Code and supplements, bound; and all other publications and maps which are printed, or otherwise reproduced, under authority of law, upon the requisition of a Congressional committee, executive department, bureau, independent office, establishment, commission, or officer of the Government. Confidential matter, blank forms, and circular letters not of a public character shall be excepted. In addition, there shall be delivered as printed to the Library of Congress: ten copies of each House document and report, unbound; ten copies of each Senate document and report, unbound; and ten copies of each private bill and resolution and fifty copies of the laws in slip form.