《资治通鉴·汉纪·汉纪十》
河间王刘德，努力钻研学问，喜好古代典籍、治学注重实事求是，用黄金丝帛购买各地的好书，购得的书，数量与汉朝廷的存书一样多。
河间王德，修学好古，实事求是，以金帛招求四方善书，得书，多与汉朝等。
Liu De, the King of Hejian, worked hard to study and was fond of ancient books. He attached great importance to seeking truth from facts in his studies and bought good books from all over the place with gold and silk. The books he bought were as many as the books stored in the Han court.