@article{Nikiforov2020how,
author={Nikiforov, V.M. and Mal'ceva, E.A.},
title={How to build a technical drawing surface with own and falling of shadows},
journal={Journal of Technical Research},
publisher={INFRA-M Academic Publishing LLC.},
year={2020},
pages={4-8},
volume={6},
issue={2},
}