Original sentence: Optimists respond that worldwide poverty is declining.The assumptions that underlie these claims, however, have been criticised<ref>M.The percentage of the world's population living on less than $1 day per day has halved in twenty years
Edited sentence: <ref>M.Optimists respond that worldwide poverty is rapidly declining.The assumptions that underlie these claims, however, have been criticized, see the article about the book.The percentage of the world's population living on less than $1 day per day has halved in only twenty years