Gao Jifu's biography in the Old Book of Tang does not specify whether the killer(s) of Gao Yuandao that Gao Jifu killed was singular or plural. See Old Book of Tang, vol. 78
Gao Jifu's biography in the Old Book of Tang and the New Book of Tang gave the name as Li Houde (李厚德), but the Zizhi Tongjian gave it as Li Yude, and the name Li Yude is generally used in tertiary sources. Compare Old Book of Tang, vol. 78, and New Book of Tang, vol. 104, with Zizhi Tongjian, vol. 186.
The New Book of Tang indicated that Gao Jifu was made a de facto chancellor at this point. See New Book of Tang, vol. 61. However, this, if true, appeared to be no longer the case after the end of the Goguryeo campaign, and could have been simply a temporary measure during the Goguryeo campaign, as he was not referred to as chancellor again until 648 when he was made the head of the legislative bureau.
