Xu Collection, Lower Volume
Radical: Eat (shí)
Kangxi Strokes: 12
Page 1416, Entry 12
Pronounced tuo.
Yu Pian (Book of Characters) states that bo-tuo is a type of baked good.
Yangzi Fangyan (Regional Speech) states that a baked good is called a tuo.
Qimin Yaoshu (Essential Techniques for the Welfare of the People) states that wheat is suitable for making bing-tuo.
Biography of Li Maozhen in the History of the Five Dynasties writes it as bu-tuo.
Wang Pizhi in Mianshui Yantan (Conversations at the Mianshui River) writes it as tuo.
Pianhai (Sea of Characters) states that it is sometimes also written in a variant form.
Textual research: Yu Pian states bo-tuo is a type of baked good. Following the original text, corrected to bo-tuo.