TCHORBADJIEFF, A.; KOTSEV , T.; STOYANOVA, V. .; TCHERKEZOVA , E. . K-means clustering of a soil sampling scheme with data on the morphography of the Ogosta valley northwestern Bulgaria. European Journal of Geography, [S. l.], v. 10, n. 2, 2019. Disponível em: https://eurogeojournal.eu/index.php/egj/article/view/183. Acesso em: 17 oct. 2025.