1. Abernathy v. Principi, 3 Vet. App. 461, 465 (1992).
2. Allen v. Principi, 237 F.3d 1368 (Fed. Cir. 2001).
3. Amberman v. Shinseki, 570 F.3d 1377 (Fed. Cir. 2009).
4. Ardison v. Brown, 6 Vet. App. 405, 407 (1994).
5. Barr v. Nicholson, 21 Vet. App. 303, 311 (2007).