Boyd, PA; Armstrong, B; Dolk, H; Botting, B; Pattenden, S; Abramsky, L; Rankin, J; Vrijheid, M; Wellesley, D; (2005) Congenital anomaly surveillance in England - ascertainment deficiencies in the national system. BMJ. p. 27. ISSN 1468-5833 DOI: https://doi.org/10.1136/bmj.38300.665301.3A