Pamphlets - classification of documents:

A pamphlet is an independent publication. It is normally a document of a few printed pages, usually less than 49. Pamphlets cover an extremely wide range of subjects, but their uniqueness is that an individual  specialised topic is dealt with precisely and concisely. It is an ideal resource for  anyone studying in depth a  specialised topic. Further, much of the information appears in pamphlets before it is incorporated in books. Pamphlets are a  current source of information and are indispensable to libraries because they may contain information not avail-able from any other source. They are relatively less expensive than  a periodical or book. Since they  contain information on a narrow subject-field and are presented in a unique manner, they are very useful to specialised users. Their usefulness, increases if they are objective and balanced in presentation.  

Patents:

In science and technology, patents form an important source of information. A patent specification  is a kind of legal protection for the inventor. In addition to a detailed description, patent specifications include  a statement of claim by an applicant regarding the scope of the monopoly he seeks to cover in his invention. The claim is relatively broad in nature, its purpose being to specify the range of products or processes that the patentee claims to monopolise. It, therefore, covers variations of the invention referred to in the patent. Thus, while a patent is a legal document, it can also be used as a source of industrial information. 

A patent is an agreement between a government and an inventor whereby the  latter discloses his invention to the public in exchange for an exclusive right of exploitation for a fixed period. Each patent presents a detailed account of a new manufacturing process, or an improvement of an existing process, a new product a new method of testing and control, etc., which may not be available in this form in other sources. 

Every nation has a Patent Office. The Patent Office at Calcutta  and its sub-offices grant over 3,000 patents  each year. The output of  each developed nation is much more. 

A comprehensive collection of national and foreign patents must be developed by all special and research libraries because  of  the following advantages: 1) They give technological information which is not found  in any other source, 2) In addition to the information on the general utility  of the invention, they inform us about the practical application of the invention in industry as also some background material, 3) They reveal information on specific technological items  more completely and earlier than other sources do.