Hoddinott, Pat, Britten, Jane, Prescott, Gordon ORCID: 0000-0002-9156-2361, Tappin, David, Ludbrook, Anne and Godden, David J (2009) Effectiveness of policy to provide breastfeeding groups (BIG) for pregnant and breastfeeding mothers in primary care: cluster randomised controlled trial. British Medical Journal (BMJ), 338 . ISSN 0959-8138