According to the Rev. John Gulick: "The inhabitants of other Asiatic nations, who have had occasion to represent the words of their several languages by Chinese characters, have as a rule used unaspirated characters for the sounds, g, d, b. The Muslims from Arabia and Persia have followed this method … The Mongols, Manchu, and Japanese also constantly select unaspirated characters to represent the sounds g, d, b, and j of their languages. These surrounding Asiatic nations, in writing Chinese words in their own alphabets, have uniformly used g, d, b, & c., to represent the unaspirated sounds."
Who have followed this method?
Muslims from Arabia and Persia