Güller, U., Warschkow, R., Ackermann, C. J., Schmied, B. M., Cerny, T. and Ess, S. (2017) “Lower hospital volume is associated with higher mortality after oesophageal, gastric, pancreatic and rectal cancer resection”, Swiss Medical Weekly, 147(2930), p. w14473. doi: 10.4414/smw.2017.14473.