Two new papers on fossil Balaenidae are available online:
Guillaume Duboys de Lavigerie, Mark Bosselaers, Stijn Goolaerts, Travis Park, Olivier Lambert & Felix G. Marx (2020) New Pliocene right whale from Belgium informs balaenid phylogeny and function. Journal of Systematic Palaeontology, DOI: 10.1080/14772019.2020.1746422
Yoshihiro Tanaka; Hitoshi Furusawa; Masaichi Kimura (2020). A new member of fossil balaenid (Mysticeti, Cetacea) from the early Pliocene of Hokkaido, Japan. Royal Society Open Science. 7 (4): Article ID 192182. doi:10.1098/rsos.192182.