Found 3 books

[en] Practical Asterisk 1.4 & 1.6 Addison-Wesley Professional

Wintermeyer, Stefan & Bosch, Stephen

[en] Practical Asterisk 1.4 and 1.6 · From Beginner to Expert Addison-Wesley Professional

Wintermeyer, Stefan & Bosch, Stephen

[en] Learn Rails 5.2 Apress

Wintermeyer, Stefan