Classification of Copper Minerals by Handheld Laser-Induced Breakdown Spectroscopy and Nonnegative Tensor Factorisation. - Michal Wójcik; Pia Brinkmann; Rafal Zdunek; Daniel Riebe; Toralf Beitz; Sven Merk; Katarzyna Cieslik; David Mory; Arkadiusz Antonczak (Sensors, 2020)