However, some recent research considers that "Jogu Shotoku Hooteisetsu" and "Gangoji Garan Engi," which were thought to be written before Shoki and to have little modification, were written after Shoki (partly because the title of 'emperor' which was used in later years was already seen), so that their positions have not been established.
ただし、書紀以前に成立した書とされ、作為が少ないと思われた『上宮聖徳法王帝説』や『元興寺縁起』についても、近年の研究において書紀以後の成立とする説も現れ（後世に用いられた「天皇」号が記載されているなど）、その地位は確定していない。