Elisabeth Kübler-Ross, M.D. (July 8, 1926 – August 24, 2004) was a Swiss-born psychiatrist, a pioneer in near-death studies, and the author of the groundbreaking book On Death and Dying (1969), where she first discussed what is now known as the Kübler-Ross model.
In this work she proposed the now famous Five Stages of Grief as a pattern of adjustment.
These five stages of grief are denial, anger, bargaining, depression, and acceptance. In general, individuals experience most of these stages, though in no defined sequence, after being faced with the reality of their impending death. The five stages have since been adopted by many as applying to the survivors of a loved one’s death, as well.

Elizabeth Kubler-Ross Foundation. Biography. Internet. Accessed on June 20, 2016.