Tennant, Peter W G, Murray, Eleanor J, Arnold, Kellyn F, Berrie, Laurie, Fox, Matthew P, Gadd, Sarah C, Harrison, Wendy J, Keeble, Claire, Ranker, Lynsie R et al (2021) Use of directed acyclic graphs (DAGs) to identify confounders in applied health research: review and recommendations. International Journal of Epidemiology, 50 (2). pp. 620-632. ISSN 0300-5771