As far as I know, both work and works may be correct in different contexts. For example, we say I had much work today. But when referring to different pieces of work we say works, e.g., related works in a paper. However, In these sentences I'm not sure which one is correct:
- This survey sheds light on the differences between our approach and the previously proposed works/work.
- Thanks to X and Y for their help in surveying the related work/works.