Firth, Alice M., O’Brien, Suzanne M., Guo, Ping, Seymour, Jane, Richardson, Heather, Bridges, Christopher, Hocaoglu, Mevhibe B., Grande, Gunn, Dzingina, Mendwas, Higginson, Irene J., Murtagh, Fliss E.M., "Establishing key criteria to define and compare models of specialist palliative care: a mixed-methods study using qualitative interviews and Delphi survey", Palliative Medicine, 2019