1. Rank preservers on spaces of symmetric matrices;Beasley;Linear Multilinear Algebra,1997
2. Mappings which preserve idempotents, local automorphisms, and local derivations;Brešar;Canad. J. Math.,1993
3. W.S. Cheung, C.-K. Li, Linear maps transforming the unitary group, Canad. Math. Bull, to appear; preprint available at http://www.resnet.wm.edu/∼cklixx/unitary.pdf
4. W.S. Cheung, C.-K. Li, Y.T. Poon, Isometries between matrix algebras, submitted
5. Two generalizations of the Gleason–Kahane–Zelazko theorem;Christensen;Pacific J. Math.,1997