Orfanogiannaki, K., Karlis, D. and Papadopoulos, G.A. 2007. Identification of temporal patterns in the seismicity of Sumatra using Poisson Hidden Markov models. Bulletin of the Geological Society of Greece. 40, 3 (Jan. 2007), 1199–1206. DOI:https://doi.org/10.12681/bgsg.16872.