Epidemiology of inflammatory bowel disease in the Songpa-Kangdong district, Seoul, Korea, 1986–2005: a KASID study - Yang, S K; Yun, S; Kim, J H; Park, J Y; Kim, H Y; Kim, Y H; Chang, D K; Kim, J S; Song, I S; Park, J B; Park, E R; Kim, K J; Moon, G; Yang, S H (Inflamm Bowel Dis, 2008)