CMU Sphinx Speech to Text Links
Sphinx training tutorial.
https://cmusphinx.github.io/wiki/tutorialam/
Another tutorial with some more HOWTOs written for Sinhala language.
https://codeliteral.wordpress.com/2016/01/02/sinhala-speech-recognition-with-cmusphinx/
Building a language model
https://cmusphinx.github.io/wiki/tutoriallm/
And tools for language models
http://www.speech.cs.cmu.edu/SLM/toolkit.html
Large scale language model for domain specific languages