Question: When was the first solo art exhibition of the author of the book Comet in Moominland ? 
Sentence (from "Comet in Moominland"): Comet in Moominland (Swedish: "Kometjakten" / "Mumintrollet på kometjakt" / "Kometen kommer") is the second in Tove Jansson's series of Moomin books.
Relevant evidence: Yes