Faynburg , G.Z., and A.G. Isaevich. “The Discovery That Changed the World (about the Role of Permian Science in the Birth and Application of Silvinite Speleoclimatotherapy)”. Perm Federal Research Centre Journal, no. 1, May 2023, pp. 59-66, https://doi.org/10.7242/2658-705X/2023.1.7.