Socioeconomic status and overweight prevalence in polish adolescents: the impact of single factors and a complex index of socioeconomic status in respect to age and sex - Kowalkowska, Joanna; Wadolowska, Lidia; Weronika Wuenstel, Justyna; Słowińska, Małgorzata Anna; Niedźwiedzka, Ewa (Iranian Journal of Public Health)