With a goal of improving retrieval in bibliographic environments, this volume takes stock of what we know about relationships in the overall bibliographic domain, with particular emphasis on relationships between subjects, relationships among bibliographic entities, and relationships between subject content and user needs. The volume presents the current state of the art in examining the expression of relationships in some of the best thesauri and classification schemes in use throughout the world. It also looks to the future by providing guidance for relational tasks now taking on greater significance, as retrieval systems increasingly operate in automated modes and as retrieval systems cross linguistic, cultural, and disciplinary boundaries. By bringing together in one place the perspectives of some of the most prominent persons working in this arena, this volume should be of interest to researchers from library and information science, as well as computer science (artificial intelligence, knowledge representation, information retrieval, natural language processing), and to many practitioners, including: developers of thesauri and classification schemes; developers of Web search engines and search directories; indexers and subject cataloguers; and professional searchers.