M. Zoran, R. Savastru, D. Savastru, C. Chitaru, M. Tautan, L. Baschir, 2012. Monitoring of radon anomalies in South – Eastem part of Romania for earthquake surveillance. Journal of Radioanalytical & Nuclear Chemistry, 293(3), pp. 769-781, doi: 10.1007/s10967-012-1780-4.