@article{ZHUKOV2017leningrad,
author={ZHUKOV, P.V. and LEBEDEVA, M.Y.},
title={LENINGRAD REGION –  THE TERRITORY OF ECOLOGICAL TOURISM},
journal={Services in Russia and abroad},
publisher={Russian State University of Tourism and Service},
year={2017},
pages={57-70},
volume={11},
issue={5},
}