《资治通鉴·唐纪·唐纪六十八》
唐西川节度使卢耽又遣同节度副使谭奉祀致书于杜元忠，质问南诏军来犯意图，杜元忠将谭奉祀扣留。
卢耽遣同节度副使谭奉祀致书于杜元忠，问其所以来之意。
Lu Dan, the Tang's Xichuan Jiedushi, again sent his deputy envoy Tan Fengsi to deliver a letter to Du Yuanzhong, questioning the Nanzhao's intentions in invading. Du Yuanzhong detained Tan Fengsi.