Oliver, A., Crespo, A., Mir, J., a., ., & Andrade, E. (1991). Neodymium fluoride film thickness changes by 7 KeV Ar$^+$ bombardment. Revista Mexicana De Física, 38(6), 938–945. Retrieved from https://rmf.smf.mx/ojs/index.php/rmf/article/view/2293