Longman Reference Guides, written by examiners, provide an easy-to-use, alphabetical listing of the vital points for each GCSE subject. They can be used for quick reference throughout the GCSE course, they cover all those ideas, terms, definitions and diagrams that are unfamiliar to students. By using this combination of a dictionary and encyclopedia, each entry is given a fully illustrated explanation. There is also extensive cross-referencing, where appropriate, giving a more complete picture of the use of a term.