1. UNICEF and WHO (2004) Low birth weights: country, regional and global estimates. UNICEF, Editorial and publication section, New York
2. Kramer M (2004) Socioeconomic determinants of intrauterine growth retardation. Eur Clin Nutr 52(S1):S21–S28
3. Wardlaw TM (ed) (2004) Low birthweight: country, regional and global estimates. Unicef
4. Central Statistical Agency (2011) Ethiopian demographic and health survey Addis Ababa Ethiopia
5. Molenberghs G, Verbeke G (2005) Models for discrete longitudinal data. Springer