Altieri, K. E., J. Burger, B. Language, and S. J. Piketh. “A Case Study in the Wintertime Vaal Triangle Air-Shed Priority Area on the Utility of the Nitrogen Stable Isotopic Composition of Aerosol Nitrate to Identify NOx Sources”. Clean Air Journal, vol. 32, no. 1, June 2022, doi:10.17159/caj/2022/32/1.12505.