7SESHAGLRL R, DEVAGUPTAPU L V. Shaped Honeycomb Structures and Method and Apparatus for Making Shaped Honeycomb Structures: Unite States, 006372332B 1 [P]. 2002- 04-16.
8ROBERT E J, LAKE Z, RAYMOND A K, et al. Method for Forming a Honeycomb Corner Protector with Self-locking Panels : U nile States, 6007469[P]. 1999-12-28.