Stadnyk V, Romanyuk M, Brezvin R. A New LiNH4SO4 Crystal with an Isotropic Point. Ukr. J. Phys. [Internet]. 2012 Dec. 15 [cited 2025 May 31];57(12):1231. Available from: https://ujp.bitp.kiev.ua/index.php/upc/article/view/2021129