provide their own apps (like Hueber Interaktiv) where you can purchase a digital license. This includes embedded audio and interactive exercises. BlinkLearning
If you need a specific exercise from a Kursbuch, describe the topic – maybe someone can explain the grammar instead. kursbuch b1 pdf
A physical book lets you write in the margins. For a PDF, use: provide their own apps (like Hueber Interaktiv) where