Reference and information services are considered an important activity of a modern library. This comprehensive and student-friendly book discusses in detail different types of information and reference sources and services, such as encyclopaedias, directories, yearbooks, dictionaries, geographical sources, biographical sources, statistical sources and handbooks. The book is organised into four parts. Part I deals with various types of information sources such as documentary and non-documentary sources. Part II discusses different types of reference services, organisation of reference section and the role of the librarian in the digital age. Part III describes the wide range of information service such as Current Awareness Service (CAS) and Selective Dissemination of Information (SDI). Part IV provides an overview of important information systems such as National Information System for Science and Technology (NISSAT) and International System for Agricultural Science and Technology (AGRIS). The book is intended for the undergraduate and postgraduate students of library science. Besides, it will also be very useful for librarians, information scientists, and information professionals. Salient Features Deals with both theoretical and practical aspects of information sources and services. Discusses various types of information sources and services keeping in view the latest trends and developments in the field. Presents the concepts related to information sources and services in a systematic and accessible way.