Gravity and muscle force operated surface ropeway: an efficient, cheap, and eco-friendly transport mode for mountainous countriesLok B. Baral, Jeevan J. Nakarmi, Khem N. Poudyal, Nava R. Karki and Dimitrios NalmpantisEur. Phys. J. Plus, 134 2 (2019) 55DOI: https://doi.org/10.1140/epjp/i2019-12438-0