Sapielkin, Victor. 2019. “Using the Method of Principal Components in Study of the Data Obtained by Means of X-Ray Fluorescent Spectral Analysis on the Elemental Composition of Clothing Damages Areas at the Shooting of Nonlethal Elastic Bullets ‘Teren-12P’ Ammunition”. Journal of Education, Health and Sport 9 (1):326-34. https://apcz.umk.pl/JEHS/article/view/6561.