BAIMOLDA DOSSAN; CECHAK TOMAS; SHYNGYSOVA SH. X-RAY FLUORESCENCE RESEARCH OF SULPHUR AND ASH CONTENTS IN THE COALS OF KAZAKHSTAN. European Research Materials, [S. l.], n. 1, 2022. Disponível em: https://ojs.publisher.agency/index.php/ERM/article/view/490. Acesso em: 30 jun. 2026.