The CARMENES search for exoplanets around M dwarfs – Planet occurrence rates from a subsample of 71 stars
https://www.aanda.org/articles/aa/abs/2021/09/aa40968-21/aa40968-21.html
Detection and Bulk Properties of the HR 8799 Planets with High-resolution Spectroscopy
https://iopscience.iop.org/article/10.3847/1538-3881/ac1349
Deep exploration of the planets HR 8799 b, c, and d with moderate resolution spectroscopy
https://arxiv.org/abs/2109.07614