《旧唐书·本纪·卷二十》
五月十一日，太清宫使柳璨上奏说 ：最近皇上敕命改换宫殿殿门的名字，臣认为玄元皇帝庙，西京长安叫作太清宫，东京洛阳叫作太微宫，请把太清宫名字恢复为太微宫，臣便于接受官阶。 
己巳，太清宫使柳璨奏： 近敕改易宫殿门名，窃以玄元皇帝庙，西京曰太清宫，东京曰太微宫，其太清宫请复为太微宫，臣便给入官阶。 
On May 11, Taqinggong emissary Liu Can reported: the emperor recently decreed the names of the palace gates be changed, but this minister thinks that the Temple to the Emperor Xuan Yuan is called Taqinggong in western capital Chang'an, and Taiweigong in eastern capital Luoyang, I request permission to change the name of Taqinggong back to Taiweigong, so that it'll be easier for me to accept my official rank.