Markowicz, Iwona, and Paweł Baran. 2019. “A Ranking of Combined Nomenclature Chapters According to Quality of Data on Intra‑Community Trade in Goods of Polish Businesses”. Acta Universitatis Lodziensis. Folia Oeconomica 4 (343):195-209. https://doi.org/10.18778/0208-6018.343.12.