[Update: This became a dead link in the first days of January, 2019]
https://www.pov-int.eu/wp-content/uploads/2016/03/2016-Dt-PoV_Trainer-Handbuch_sec.pdf
The 2016 edition can also be found here:
https://docplayer.org/31191330-Psychology-of-vision-trainerhandbuch-2016.html
