TCHORBADJIEFF, Assen, Tsvetan KOTSEV, Velimira STOYANOVA, and Emilia TCHERKEZOVA. “K-Means Clustering of a Soil Sampling Scheme With Data on the Morphography of the Ogosta Valley Northwestern Bulgaria”. European Journal of Geography 10, no. 2 (January 1, 2019). Accessed October 17, 2025. https://eurogeojournal.eu/index.php/egj/article/view/183.