The rapid increase in the volume of documents and the development of scientific fields have led to the emergence of various methods for recording their information content. It is impossible for researchers in different scientific fields to study all the documents published in their area of expertise. In many cases, there is not even time to read abstracts of articles and research reports. Furthermore, countless research projects have been conducted in various parts of the world with no trace of them available. Given the above, and to prevent duplication of effort and to increase speed and accuracy in research activities, information science experts decided to provide a record of every scientific document using various means. A scientific document can be recorded in various ways, including the author, title, research organization or publisher, an indicative abstract, or a comprehensive abstract, among others.