Roggero, P., N. S. Reyes, K. Figueroa, and R. Paredes. “List of Clustered Permutations in Secondary Memory for Proximity Searching”. Journal of Computer Science and Technology, vol. 15, no. 02, Nov. 2015, pp. p. 107-113, https://journal.info.unlp.edu.ar/JCST/article/view/546.