Evidence confirms an anthropic origin of Amazonian Dark Earths by Lombarto, U, Arroyo-Kalin, M, Schmidt, M, Ramsey, CB

Electron Paramagnetic Resonance spectroscopy by Calle, C, Eichel, R, Finazzo, C, Forrer, J, Granwehr, J, Gromov, I, Groth, W, Harmer, J, Kalin, M, Lammler, W, Liesum, L, Madi, Z, Stoll, S, Van Doorslaer, S, Schweiger, A