Recommend please a book on voip in java?

Question

Java

Please recommend a suitable book that will introduce you to voip in java (with examples and the ability to download source code from github).
Language Russian and English.

Answer 1

VoIP Deployment for Dummies
online.slidehtml5.com/lpod/lbrj/lbrj.pdf
Project 4: VoIP Chat program
www.cs.sun.ac.za/rw354/ASSIGNMENTS/Assignment4.pdf
https://ssearch.oreilly.com/ ?i=1;q=voip&act=pg_1