《史记·十二本纪·吕太后本纪》
三年，开始修筑长安城，四年，修完了一半，五年六年，全部完工。
三年，方筑长安城，四年就半，五年六年城就。
In the third year, they started to build Chang'an city. In the fourth year, they had completed half of it. In the fifth and sixth years the whole thing was completed.