摘要:ackground. While the use of citations for assessing research impact is well-studied, there is little work that investigates the content introduced into the citing documents through citationsthe linguistic expressions used to represent the cited content Objectives. This study analysed the types of content introduced into citing documents using the citations (cited content)units of linguistic expressions used to represent the cited content. Methods. We classified the expressions representing the cited content according to the unit of linguistic expressions (termsclauses)classified the cited content into conceptual categories. We adopted different frameworks for the classification of cited content represented by termsclauses. The categories for terms were domain specificthe categories for clauses took into account subjectivitygenerality. We also described the detailed categories of cited content with examplesprovided seven types of cited content for clauses. Results. We found that among the expressions representing cited content, terms constituted about 40%clauses constituted about 60%. The majority of the cite terms were domain specific;35% of the cite terms referred to unique concepts. Of the cite clauses, 50% were objectiveterm-specific, 40% were objectivegeneral,10% were subjective. Contributions. This research provided a description of cite unitselaborated on the categories for cited content. The results showed basic types of cited contentclarified the distribution of cite units.