@article{Ivanov2017revisited,
author={Ivanov, V.A.},
title={REVISITED THE EVOLUTIONARY AND PERSPECTIVE DEVELOPMENT OF EXTREME SPORTS IN THE TYUMEN REGION},
journal={Bulletin of Nizhnevartovsk State University},
publisher={Nizhnevartovsk State University},
year={2017},
pages={74-79},
volume={},
issue={3},
}