The Senate's procedures are determined not only by its standing rules, but also by its standing orders, published precedents, committee rules, and informal practices. Constitutional mandates and rule-making statutes also impose procedural requirements on the Senate, and rules of Senate party conferences can sometimes affect committee and floor action. Parliamentary reference sources set forth the text of these authorities or provide information about how and when they govern different parliamentary situations. This book discusses the coverage, format, and availability of three types of Senate parliamentary reference sources: official sources such as the Senate Manual and Riddick's Senate Procedure; publications of committees and offices of the Senate; and rules of party conferences. The book also reviews some key principles of Senate parliamentary procedure that bear on appropriate use of these sources. Summaries and appendices provide citations to print and electronic versions, and list related Congressional Research Service (CRS) products. The Senate sets forth its chief procedural authorities in the Senate Manual, a new edition of which appears periodically as a Senate Document and is distributed to Senators' and committee offices. Among these authorities, the Senate also publishes its Standing Rules as a separate document, and the Constitution is available in an annotated edition prepared by CRS. The Manual also contains more specialised authorities, such as permanent standing orders, rules for impeachment trials, and a manual of procedures related to House-Senate conferences. Other Senate procedural authorities include Riddick's Senate Procedure, last published in 1992 but with online updates, which offers a topically ordered digest of precedents interpreting Senate procedures and standard forms for procedural action. The Senate also often regulates itself through orders entered by unanimous consent, either as standing orders or for the consideration of individual measures; these can often most readily be found in the Congressional Record. Some statutes contain "rule-making" provisions that act as procedural authorities, though no Senate source compiles all of them. Each committee adopts its own written rules, which are published in the Record and compiled, in each Congress, in Authority and Rules of Senate Committees, a print of the Committee on Rules and Administration. Other Senate committee prints, which provide supporting information on elements of Senate procedure, include Budget Process Law Annotated, the Senate Cloture Rule, and Treaties and Other International Agreements. The parliamentarians in both chambers have prepared concise summary documents on procedure in the legislative process. In the Senate, currently only the Republican Conference appears to have adopted written rules.