From astronomy to zoology, the Oxford Paperback Reference series is unrivalled in its scope and diversity. Over 100 different subject reference dictionaries offer a wealth of essential information for teachers, students, and interested amateurs. Each subject is covered in depth over several thousand A to Z entries, offering authoritative explanations of all the terms you're likely to encounter, including in-depth entries for broader concepts. Extras include chronologies, maps, and appendices of useful additional information. Many titles also now offer reliable and trustworthy web links which are updated via their free companion webpage.