《旧唐书·本纪·卷七》
十八日，殿中监窦怀贞为左台御史大夫、同中书门下平章事。
壬戌，殿中监窦怀贞为左台御史大夫、同中书门下平章事。
On the 18th, Supervisor of the Inner Palace Dou Huaizhen was made Left Grand Secretary of the Imperial Secretariat and Co-director of the Bureau for Legislative Affairs at the Secretariat.