In this case, the teacher must confirm the following in writing by email:
"I hereby confirm _________________ [Name] that each and every one of my course participants has bought the equivalent print product from Ernst Klett Sprachen in the last 6 months, and that the digital edition ordered here at a special price can only be used in combination with a purchased print course used in class at my institution _________________ [name].
I also confirm to ensure that course participants who have not bought an equivalent print product from Ernst Klett Sprachen GmbH will not receive the digital version in the Media bundle at a special price from me. If the digital product is used as stand-alone, it can be purchased at full price from Ernst Klett Sprachen GmbH or a registered dealer of Ernst Klett Sprachen GmbH at the respective national price.
If this agreement is not observed, Ernst Klett Sprachen GmbH reserves the right to terminate the digital license with immediate effect."