Andresen, K, Carreira, H and Mcdonald, H (2022). Clinical codelist - Autoimmune disease (Read). [Data Collection]. London School of Hygiene & Tropical Medicine, London, United Kingdom. https://doi.org/10.17037/DATA.00002791.

Forbes, H, Bhaskaran, K, Thomas, SL, Smeeth, L, Clayton, T and Langan, S (2014). Clinical code list - Inflammatory Bowel Disease codes. [Data Collection]. London School of Hygiene & Tropical Medicine, London, United Kingdom. https://doi.org/10.17037/DATA.149.

Iwagami, M and Tomlinson, LA (2020). Clinical codelist - Inflammatory bowel disease codes. [Data Collection]. London School of Hygiene & Tropical Medicine, London, United Kingdom. https://doi.org/10.17037/DATA.00001679.