Full text: Available Index: IMSEAR (South-East Asia) Main subject: Humans / Case-Control Studies / Mass Screening / Epidemiologic Methods / Epidemiology / Sampling Studies / Health Status Indicators / Health Services Research / India Type of study: Etiology study / Observational study / Risk factors / Screening study Country/Region as subject: Asia Language: English Journal: Indian Pediatr Year: 1991 Type: Article