Book, has spine, which is folded in V shape such that both spine and covers are arranged in M-shape in closed condition, where fold that is parallel to two other folds is provided in area of spine

摘要

The book has a fold (6) between an upper cover (1) and spine (3), and a fold (7) provided between a lower cover (2) and spine. The spine attaches ring shaped retaining units (10) with a gap (17), in which units were hung. A fold (8) parallel to folds (6,7) is provided in an area of the spine. The spine is folded in V shape in such a manner that both spine and covers are arranged in M-shape in closed condition.