@article{196398,
      author       = "Douša, Jan and Václavovic, Pavel and Zhao, Lewen and
                      https://www.mdpi.com/2220-9964/10/8/516",
      title        = "Accuracy Evaluation of Ionospheric Delay from Multi-Scale
                      Reference Networks and Its Augmentation to PPP during Low
                      Solar Activity",
}