[1]
A. M. El Kenawy, M. F. McCabe, S. M. Vicente-Serrano, J. I. López-Moreno, and S. M. Robaa, “Changes in the frequency and severity of hydrological droughts over Ethiopia from 1960 to 2013”, CIG, vol. 42, no. 1, pp. 145–166, Jun. 2016.