"Big Soviet Encyclopedia (SD)" is a huge collection of knowledge about the most diverse aspects of life and science. This encyclopedia, consisting of 65 volumes, became a model of reference literature for generations of Soviet citizens. It contains information from various fields of knowledge - from history and politics to science and culture. Each new edition of the "Great Soviet Encyclopedia" is filled with interesting facts, details and illustrations, making each volume extremely interesting for readers of all ages. To this day, "Bolsha Soviet Encyclopedia (SD)" remains an important source of knowledge and helps expand the horizons of its readers.