Sucharova, J., Suchara, I., Hola, M., Reimann, C., Boyd, R., Filzmoser, P., & Englmaier, P. (2011). Linking chemical elements in forest floor humus (Oₕ-horizon) in the Czech Republic to contamination sources. Environmental Pollution, 159(5), 1205–1214. https://doi.org/10.1016/j.envpol.2011.01.041