Long range correlation in earthquake precursory signals H. Chaudhuri, C. Barman, A.N.S. Iyengar, D. Ghose, P. Sen and B. Sinha Eur. Phys. J. Special Topics, 222 3-4 (2013) 827-838 Published online: 11 July 2013 DOI: 10.1140/epjst/e2013-01886-y