Jacobsen, P;    Wood, L;      (2020)    Risk of contamination when planning psychological therapy trials can be assessed using a simple framework.                   Journal of Clinical Epidemiology , 124    pp. 8-15.    10.1016/j.jclinepi.2020.04.005 <https://doi.org/10.1016/j.jclinepi.2020.04.005>.       Green open access