Electronic data banks make the research scientist's everyday work much easier. To seek and find desired information, however, calls for a knowledge of the internal structure of a data bank. The first part of the book deals with this topic. The author leads the reader through the architecture of on-line data banks that are vital for natural scientists. He explains their structure in a step-by-step fashion and presents the basic concepts of data-bank theory. The second part illustrates how the scientist's PC can extract information. Using the many examples of searches in various data banks, even a user with little interest in theory can achieve success on-line.