Abstract: A system and method are provided for comparing portions of document text with potential citation components, determining if individual portions correspond to a citation component, and determining if a set of portions correspond to a valid citation pattern. A set of valid citation patterns is provided. Each citation pattern may include a specified combination of citation components. The invention further relates to identifying potential citation components from text in a document, analyzing a pattern of the identified citation components by comparing the pattern to a set of stored citation patterns to determine if the potential citation is a type of citation, and if so, is it a valid (and/or invalid) citation pattern. Once citation patterns have been determined in the document, annotations may be inserted into the document, and subsequent action may be taken, for example, generating a list of citations, providing research services, error-handling, and/or providing other options related to the citations.