Higginson, Irene, Wilcock, Andrew, Johnson, Miriam J., Bajwah, Sabrina, Lovell, Natasha, Yi, Deokhee, Hart, Simon, Crosby, Vincent, Poad, Heather, Currow, David, Best, Emma, Brown, Sarah, "Randomised, double-blind, multicentre, mixed-methods, dose-escalation feasibility trial of mirtazapine for better treatment of severe breathlessness in advanced lung disease (BETTER-B feasibility)", Thorax, 2020