1. (1) “Strain measurements of structural materials” by Bjorn Bergqvist and Gosta Scherling; Strain, July, 1966.
2. (2) G. & E. Engineering Ltd., Clapham.
3. (3) A. Grindrod (verbal correspondence), Berkeley Nuclear Laboratories.
4. (4) B.A.C. (Operating) Ltd., Internal report.
5. (5) Concordia Electric Wire and Cable Co. Ltd., Long Eaton.