A preliminary study of indoor radon levels at historical area of Shkodra cityM. Kuqali, Gj. Rrota, G. Nafezi, Dh. Kuqi and Denisa SalillariEur. Phys. J. Spec. Top., (2025) 1-6DOI: https://doi.org/10.1140/epjs/s11734-025-01718-5