Preliminary results of radon concentration monitoring in selected Slovak caves and galleriesJ. Lüley, I. Smetanová, V. Vrtalová, P. Blahušiak, B. Vrban, Š. Čerba, O. Glavo, F. Révai, K. Csicsay and V. NečasEur. Phys. J. Spec. Top., (2026) 1-10DOI: https://doi.org/10.1140/epjs/s11734-026-02354-3