Long range correlation in earthquake precursory signalsH. Chaudhuri, C. Barman, A.N.S. Iyengar, D. Ghose, P. Sen and B. SinhaEur. Phys. J. Special Topics, 222 3-4 (2013) 827-838DOI: https://doi.org/10.1140/epjst/e2013-01886-y