1. Bruera E, et al., editors. The textbook of palliative medicine and supportive care. 2nd ed. Taylor and Francis Group; 2016. p. 3–9, 95–103, 120–121, 529–535, 645–648, 691–699, 777–783.
2. Maxwell TL, Martinez JM, Knight CF. UNIPAC 1: The hospice and palliative medicine approach to life-limiting illness. 4th ed. (Porter Storey C Jr, editor). American Academy of Hospice and Palliative Medicine; 2008. p. 9–11.
3. Kuber-Ross E. On death and dying. Macmillan; 1969. p. 10.
4. Loscalzo MJ. Palliative care: an historical perspective. Hematol Am Soc. 2008;1:465.
5. National Hospice and Palliative Care Organization. NHPCO facts and figures. National Hospice and Palliative Care Organization; 2019.