Intercomparison of indoor radon measurements under field conditions in the framework of metroradon european project, Rabago, D., Fuente I., Celaya S., Fernandez A., Fernandez E., Quindos J., Pol R., Cinelli Giorgia, Quindos L., and Sainz C. , International Journal of Environmental Research and Public Health, Volume 17, Number 5, (2020)