Build Automatic Speech Recognition (ASR) from scratch [closed]

Question

I want to build a Automatic Speech Recognition (ASR) engine for myself, but I've no idea from where to start.

I've read that most ASR's are build upon Hidden Markov Models, but also I've read that HMM is limited somehow and a better approach is to build a ASR upon Machine Learning features.

Overall I am confused.

Can someone recommend me books on topics from which I can start?

Thanks (: