Hagner, Michael Department Experimental Systems and Spaces of Knowledge, Max Planck Institute for the History of Science, Max Planck Society;
Hagner, M. (1999). Review of: Schwarz, Ingo and Wenig, Klaus (eds.): Briefwechsel zwischen Alexander von Humboldt und Emil du Bois-Reymond. Berlin: Akademie-Verl. 1997. NTM, N.S. 7(1), 53.