Friedemann Schulz von Thun
Friedemann Schulz von Thun (born August 6, 1944 in Soltau) is a German psychologist and expert in inter- and intrapersonal communication. Schulz von Thun worked as a professor of psychology at the University of Hamburg until his retirement on 30 Sep.
Source: Wikipedia — Friedemann Schulz von Thun (CC BY-SA 4.0)