Answer
Being and Nothingness is not a major work of Martin Buber but of the existentialist philosopher Jean-Paul Sartre. Sartre's work explores themes of human existence, freedom, and consciousness. Buber, on the other hand, is known for his contributions to existential philosophy and his focus on the concept of the I-Thou relationship. His major works include "I and Thou," "Between Man and Man," and "Hasidism and Modern Man."