Xú Zǐdōng 徐子東, son of 徐總幹 “Xú Zǒnggàn” (the Comptroller-Xú), the unidentified author of Yì chuán dēng 易傳燈 (KR1a0044). Wrote the preface dated Bǎoyòu dīngsì (1257) mid-spring sixteenth day that is the principal source for the father’s biography (Wùzhōu Dōnglái-school discipleship under 呂祖謙 Lǚ Zǔqiān, 唐仲友 Táng Zhòngyǒu, and 宋真卿 Sòng Zhēnqīng). Cut the woodblocks of the Yì chuán dēng posthumously.