Achoyan, Zh. A., V. Zh. Achoyan, and O. A. Avetisyan. 2006. “ON SOME QUESTIONS FOR HORIZONTAL DRAIN CALCULATION”. Proceedings of the YSU C: Geological and Geographical Sciences 40 (2 (210). Yerevan, Armenia:136-38. https://doi.org/10.46991/PYSU:C.2006.40.2.136.