Introduction
Claussen C, Fahlbusch R, Felix R, Grumme T, Heinzerling J, Iglesias-Rozas J, Kazner E, Kretzschmar K, Laniado M, Lanksch W, Müller-Forell W, Newton T, Schörner W, Schroth G, Schulz B, Stochdorph O, Sze G, Wende S. Introduction. 1989, 1-1. DOI: 10.1007/978-3-642-74311-5_1.Peer-Reviewed Original Research