The evolution of the information environment in research and development at the beginning of the next millennium is dominated by the change of medium from printed to digital information and by the diversification of the information environment. This change of paradigm (the so-called end user revolution) is accompanied by extended efforts for literature and information searches. The lack of transparency in the information environment, the bewildering variety of media and the enormously expanded methodological efforts for literature searches by scientists have to be balanced by information specialists in the libraries. In the next millennium, scientists will only search for information in one single electronic search user-interface for all available sources and media at one time. Knowledge and information have always been the most important resource in science. However, the change in the methods of science has also been accompanied by a change in the method of scientific information retrieval. This article shows how a scientist’s efforts, tools and methods have changed in the past few decades for the verification and retrieval of literature and information required against the background of changing media. An outlook shows possible constellations in the next millennium.