Query: When did comic strips start appearing in hardback collection volumes?
Context: 1900 saw the debut of the Jiji Manga in the Jiji Shinpō newspaper—the first use of the word "manga" in its modern sense, and where, in 1902, Rakuten Kitazawa began the first modern Japanese comic strip. By the 1930s, comic strips were serialized in large-circulation monthly girls' and boys' magazine and collected into hardback volumes.