"Big Soviet Encyclopedia" is a well-known reference publication that was published in the USSR between 1926 and 1990. The encyclopedia consists of more than 100,000 articles on various topics: history, science, culture, technology, geography, and others. The project began in the era of Soviet constructivism and reflected all aspects of life in the USSR. The "Great Soviet Encyclopedia" was largely ideologically oriented, because the development and editing took place in accordance with the rapidly growing demands of the Soviet political power. The encyclopedia had the status of an authoritative source of knowledge for Soviet society and reflected the views and ideology of that time. Now the "Great Soviet Encyclopedia" remains an important source for studying the history, culture and mentality of the past era. Although some of the information may be out of date, the encyclopedia is a valuable testament to that time.