1. Behrend, D., A. Rius, R. Haas, L. P. Gradinarsky, J. M. Johansson, and S. J. Keihm, Comparison of independently derived atmospheric parameters, IUGG XXII General Assembly, Birmingham, England, 1999.
2. Cucurull, L. and F. Vandenberghe, Comparison of PW estimated from MM5 and GPS data, MM5 Workshop ’99, Boulder, Colorado, U.S.A., 1999.
3. Cucurull, L., B. Navascues, G. Ruffini, P. Elósegui, A. Rius, and J. Vilà, On the use of GPS to validate NWP systems: the HIRLAM model, J. Atmos. and Ocean. Tech., 17(6), 773–787, 2000.
4. Elósegui, P., A. Rius, J. L. Davis, G. Ruffini, S. J. Keihm, B. Bürki, and L. P. Kruse, An experiment for estimation of the spatial and temporal variations of water vapor using GPS data, Phys. Chem. Earth, 23(1), 125–130, 1998.
5. Emardson, T. R. and H. J. P. Derks, On the relation between the wet delay and the integrated precipitable water vapor in the European atmosphere, Meteorol. Appl, 6, 1–12, 1999.