@article{Pottiaux:3720,
      author        = "Pottiaux, Eric",
      title         = "{Precise Slant tropospheric Path Delays (SPD), Zenith
                       tropospheric Path Delay (ZPD) and horizontal gradients
                       (GRD) database for Data Assimilation Trials at KNMI.}",
      year          = "2017",
}