Book of Sui
Elsewhere, the name was used for the Ryukyu Islands in general or Okinawa, the largest of them; indeed the name "Ryūkyū" is the Japanese form of "Liúqiú". The name also appears in the "Book of Sui" (636) and other early works, but scholars cannot agree on whether these references are to the Ryukyus, Taiwan or even Luzon.