1. H. Yanagita, K. Itoh, E. Ishikawa, H. Aoki, H. Toratani, in Technical Digest of Conference on Optical Fiber Communication, 1995, paper PD2
2. P.C. Becker, M.M. Broer, V.G. Lambrecht, A.J. Bruce, G. Nykolak, in Technical Digest of Topical Meeting on Optical Amplifiers and their Applications, 1993, paper PDP5
3. Low-loss fluorozirco-aluminate glass fiber