Using this photo   The thumbnail photo (128x192 pixels) on this page may be freely used for personal or academic purposes without prior permission under the Fair Use provisions of US copyright law as long as the photo is clearly credited with © 2021 Jörn Köhler. For other uses, or if you have questions, contact Jörn Köhler joern.koehler[AT]hlmd.de. (Replace the [AT] with the @ symbol before sending an email.)