Fallon, M T, Diernberger, K, Leng, M, Hall, P S, Allende, S, Sabar, R, Versategui, E, Gordon, D, Grant, L, Lee, R, McWilliams, K, Murray, G, Norris, L, Reid, C, Sande, T, Caraceni, A, Kaasa, S & Laird, B J A 2022, ' An international, multicentre, open randomised parallel group trial comparing a two-step approach for pain relief versus the standard three-step approach of the WHO analgesic ladder in patients with cancer ', Annals of Oncology, vol. 33, no. 12, pp. 1296-1303 . https://doi.org/10.1016/j.annonc.2022.08.083