The UNISIST model of information dissemination was proposed in 1971 by the United Nations.
[1] UNISIST (United Nations International Scientific Information System) is a model of the social system of communication, which consists of knowledge producers, intermediaries, and users.
These groups of people (or actors) are different kinds of professionals.
The actors are communicating in both formal and informal ways and they are producing different kinds of documents such as journal articles, books, book reviews, proceedings, bibliographies and catalogues, dictionaries, handbooks, encyclopedias and review articles.
The UNISIST model can be used to define relations between various kinds of scientific and scholarly documents and to compare various domains and their discursive practices.