@dataset{hadas_2021_5190072, author = {Hadas, Tomasz}, title = {{Real-time ZTD and gradients from 20 IGS stations; year 2019}}, month = aug, year = 2021, publisher = {Zenodo}, version = 1, doi = {10.5281/zenodo.5190072}, url = {https://doi.org/10.5281/zenodo.5190072} }