Journals can contain information which may be too specialised or too recent to have been published in books. By using Search Engines and Gateways you will also find many useful sites yourself. However, remember that anyone can publish on the Internet. There are vast quantities of a variety of information available in cyberspace. Because of this it is very important to carefully evaluate resources for quality and authenticity.
Many organisations make their technical reports available for general use.
If you are lucky the indexes you use will cover articles published in the last 20-30 years. If you are doing a thorough search on a topic, you may need to consult a paper index that covers earlier material. Please let us know if you need to find indexes that cover older material, or help in selecting the most appropriate index for your topic. The printed version is available from 1946 to 1995. This scheme groups books together by subject.