Sima, M., Dold, B., Frei, L., Senila, M., Balteanu, D., & Zobrist, J. (2011). Sulfide oxidation and acid mine drainage formation within two active tailings impoundments in the Golden Quadrangle of the Apuseni Mountains, Romania. Journal of Hazardous Materials, 189(3), 624-639. https://doi.org/10.1016/j.jhazmat.2011.01.069