Childe Harold's Pilgrimage
Childe Harold's Pilgrimage was one of the works of Lord Byron. When the Thirteenth Doctor visited Villa Diodati in 1816, Byron was believed that she was after the third canto of the title, which he referred to as a work in progress. The Doctor clarified that she wasn't after his work because it was rather long, but complimented Byron on the work's mention of his daughter Ada, prompting him to ask if she knew of his daughter. (TV: The Haunting of Villa Diodati)
Behind the scenes
In real life, Childe Harold’s Pilgrimage was a long narrative poem published in four installments between 1812 and 1818. Canto III was written in 1816 and opens with the lines "Is thy face like thy mother's, my fair child! ADA! sole daughter of my house and heart?"