Donna Noble kept a diary during her travels with the Tenth Doctor. After the Doctor wiped her memory of him and their travels together following the Human-Time Lord Meta-Crisis, her grandfather, Wilfred Mott, took the diary from her to stop her from remembering.
Wilf believed that the diary should still be shared, as he thought that everything she had written was "so Donna". Excerpts from the diary were included in a book that the Thirteenth Doctor wrote for her next incarnation. (PROSE: A Short History of Everyone)