Moura, Marcos, e Sirlane Aparecida Abreu Santana. 2022. “Preparation of in-House Reference Material of Fe, Ca, Ni, and Si in Carbon Samples from an Aluminum Industrial Facility and the Results of a Proficiency Test”. Revista E-TECH: Tecnologias Para Competitividade Industrial - ISSN - 1983-1838 15 (2). https://doi.org/10.18624/etech.v15i2.1169.