Furthermore, the project retrodigitized the index entries of 25 editions (corrspondence, documents, diary excerpts) of Alexander von Humboldt research published between 1973 and 2016 and made them available in the digital index. These index information of the printed editions is part of the series first published by the Akademie-Verlag and finally by De Gruyter <ref xmlns="http://www.tei-c.org/ns/1.0" target="https://www.degruyter.com/view/serial/BAHF-B"><hi rendition="#i">Beiträge zur Alexander-von-Humboldt-Forschung</hi></ref>, edited by the Alexander-von-Humboldt-Forschungsstelle (1970-2014) of the BBAW.