1. P.W. France (Ed.), Optical Fibre Lasers And Amplifiers, Blackie, London, ISBN 0-216-93157-6, 1991
2. P.C. Becker, M.M. Broer, V.C. Lambrecht, A.J. Bruce, G. Nykolak, Pr3+:Ga–La–S: a promising material for 1.3 μm amplification, in: Technical Digest of Topical Meeting: Optical amplifiers and their applications Optical Society of America, Washington, DC, 1992 (Post-deadline paper PDP5)
3. Extrusion of glass
4. Flow behaviour of glass during extrusion