For the uninitiated: MAME VST isn't an official product from the MAME team. Rather, it is a wrapper or a set of audio drivers that allows a Digital Audio Workstation (DAW) to communicate directly with MAME’s sound core.
If you are looking for the "VST" specifically, it is often managed via third-party wrappers or specific synth plugins that emulate arcade chips: mame vst upd
If you need an academic paper on in emulation contexts: For the uninitiated: MAME VST isn't an official