Patents 

Patents are  an important source of information. Various primary and secondary journals publish information regarding current patents in specific subject fields. Official gazetteers of  patent offices of various countries are valuable sources of patent information. A few examples of sources of patent information are: 

Official Gazette of U.S. Patent Office 

Chemical Abstracts - Cites important patents granted in all countries pertaining to chemical industry. 

HOUGHTON (Bernard).  Technical information sources: A guide to patents, standards and technical report literature.

Standards and Specifications:

Standards and specifications are documents which state how materials and products should be manufactured, defined, measured or tested. They are documents which lay down sets  of conditions which should be fulfilled. Examples of sources of information pertaining to standards are given below: 

Catalogue of American Standards. American Standards Association. 

British Standard Year Book. British Standards Institute. 

Most national standardizing bodies publish an annual list of their standards in a year book or a catalogue.