杜佑
When the official Han Hui () served as surveyor of the Henan region (), the region immediately south of the Yellow River, he invited Quan Deyu to serve as his secretary. Early in the "Zhenyuan" era (785-805) of Emperor Daizong's son Emperor Dezong, Quan served on the staff of Li Jian () the governor (觀察使, "Guanchashi") of Jiangxi Circuit (江西, headquartered in modern Nanchang, Jiangxi). When his term of service under Li Jian finished, two other regional governors, Du You and Pei Zhou () both invited him to serve on their respective staffs whilst both their requests for his service arrived at the capital Chang'an at the same time. As Emperor Dezong had also heard that Quan had a good reputation, he summoned Quan to serve as "Taichang Boshi" (), a consultant at the Ministry of Worship (太常寺, "Taichang Si"), and later as "Zuo Bujue" (), a low-level consultant at the Chancellory, also known as the Edict Examination Bureau (門下省, "Menxia Sheng").