Mother does so much work by herself."[1] Hammarsten-Jansson's death in 1970 profoundly impacted her daughter's writing and it has been suggested that her presence is strongly felt in a number of the books Tove wrote after the death.[2] The melancholic Sent i November (1970) deals themes of leaving and loneliness, and is typically considered the most mature of the Moomin series.[3] Sommarboken (1972) concerns a young girl whose mother has died and her relationship with her grandmother. Hammarsten-Jansson's death marked the end of the Moomin series of novels and Jansson's literary output became primarily adult-oriented.[2]