《史记·八书·历书》
如今有关天文历法这方面的典籍缺少，礼乐废弛，朕深觉遗憾。
书缺乐弛，朕甚闵焉。
Nowadays, there is a lack of canonical literature on astronomy and the calendar, and ceremonies and music have fallen into disuse. I find this deeply regrettable.