URL https://www.researchgate.net/profile/Wioleta-Krupowicz/publication/315524041/figure/fig1/AS:557646745145344@1509964752690/Proposals-for-the-location-of-rural-roads-in-an-area-with-diverse-land-relief-a-roads_Q640.jpg
URL2https://www.researchgate.net/figure/Proposals-for-the-location-of-rural-roads-in-an-area-with-diverse-land-relief-a-roads_fig1_315524041
