Relevant to Habits for improving productivity.
https://doi.org/10.1111/jopy.12645
https://doi.org/10.1038/s41467-018-08259-7
https://doi.org/10.1007/s11920-018-0925-8
https://doi.org/10.1038/s41598-018-28616-2
https://doi.org/10.3109/07420528.2011.607375
There's definitely more out there, these are just the ones I looked at before writing the post.