Kant: From the book The Historian’s History of the World; Socrates: From the book A General History for Colleges and High Schools; Confucius: Sung Kyun Kwan University, Seoul, Korea
Kant: Từ sách The Historian’s History of the World; Socrates: Từ sách A General History for Colleges and High Schools; Khổng Tử: Trường Đại Học Sung Kyun Kwan, Seoul, Hàn Quốc