Frank-Walter Steinmeier, Federal President. 2019. «Address on the Opening Alexander Von Humboldt Season in Quito, Ecuador, on 13 February 2019 (With an Introduction by Ottmar Ette)». HiN – Alejandro De Humboldt En La Red. Revista Internacional De Estudios Humboldtianos 20 (38): 23-30. https://doi.org/10.18443/283.