@article{VandenBroeck:7105,
      author        = "Vanden Broeck, Grégory and Bechet, Sabrina and Clette,
                       Frédéric and Rauw, Gregor  and Schröder, Klaus-Peter 
                       and Mittag, Marco",
      title         = "{Relationship between TIGRE solar S-index and USET Ca II K
                       full disk images}",
      year          = "2024",
}