1980
Jean Piaget, Swiss psychologist and philosopher (born 1896)
Jean Piaget, Swiss psychologist and philosopher (born 1896)
Jean Piaget, Swiss psychologist and philosopher (born 1896)
Swiss psychologist (1896–1980)
Jean Piaget, Swiss psychologist and philosopher (born 1896)
Jean Piaget, Swiss psychologist and philosopher (born 1896)
Jean Piaget, Swiss psychologist and philosopher (died 1980)
Jean Piaget, Swiss psychologist and philosopher (died 1980)