Boselli, M., and M. Shukla. “Ashcroft Model Potential Study of Lattice Dynamics of $\alpha$-Iron and Barium”. Revista Mexicana De Física, vol. 45, no. 1, Jan. 1999, pp. 31-33, https://rmf.smf.mx/ojs/index.php/rmf/article/view/2821.