All the government publications are referred to as the government sources of information. A government publication is that which is issued at government expense or published by the authority of a government body. In all the major countries, any publication in serial, book or non-book form bearing the imprint of a government, whether central, state, local or foreign and of inter-governmental organizations such as UNESCO, etc., is referred to as a government publication. These publications are authoritative, at times available free of cost and are of great value to the researchers.
Amongst the government publications, a classification of documents is referred to as official publications, which are issued by a government or a government department and many times as serial publications. They are in form of parliamentary documents, reports, journals, legislative papers, administrative publications, reports from the central or state governments, bodies of law, hand-books, and decisions of Courts of Justice. The instances of government publications are various, as lots of publications are coming from United States, Great Britain and Indian governments.