"Helmut Kloos, PhD, formerly Associate Professor of medical geography, Department of Geography, Addis Ababa University; presently Research Associate, Department of Epidemiology and Biostatistics, University of California, San Francisco.
Zein Ahmed Zein, Dr Med, MPH, formerly Associate Professor of public health and Dean, Gonder College of Medical Sciences, Gonder; presently Research Associate, UNICEF, Sana’a, Yemen."