Elisabeth Kübler-Ross (July 8, 1926 – August 24, 2004) was a Swiss-American psychiatrist, a pioneer in near-death studies, and author of the internationally best-selling book, On Death and Dying (1969), where she first discussed her theory of the five stages of grief, also known as the "Kübler-Ross model". In 1970, Kübler-Ross delivered the Ingersoll Lecture at Harvard University, focusing on her book, On Death and Dying. By July 1982, Kübler-Ross had taught 125,000 students in death and dying courses in colleges, seminaries, medical schools, hospitals, and social-work institutions.
https://en.wikipedia.org/wiki/Elisabeth_K%C3%BCbler-Ross