How to create a sample vocal synthesizer?

Question

Programming

I'm fond of vocal synthesis programs (Utau, Vocaloid, SynthV). I have already created several voicebanks for utau and deepvocal, thanks to which I superficially understand the principles of operation of such programs (for example, types of voicebanks: vsv, svvs, ArpaBet...). Also, I'm starting to learn programming, and I dream of creating the same synthesis engine as these programs have.
Please suggest literature, articles, libraries for languages ​​to make this possible.