In 1922 he received a PH.D. in the history of ar… Jean Piaget , Together with Sigmund Freud and B. F. Skinner, Jean Piaget (1896-1980) was one of the three most influential psychologists of the twentieth century.…
…………………………………………………………………………………………………………. यो मुलुक सिंगापुर जस्तो बनिसकेको छैन मात्र राजनीतिक परिवर्तन...