1. J. Anderson and al. (1964) Brit. J. Radiol., 37, 957.
2. H.L. Atkin (1965) Matter Evaluation, 22, 453.
3. J.P. Barton (1965) Symposium on physics and non destructuve testing September 1965, published by I.T.T. Research Institute, Chicago,Illinois.
4. J.P. Barton (1967) Neutron Radiography Newsletter. American Society for non destructive testing, n°7.
5. J.P. Barton (1969) Proceeding 16th conference on remote systems technology. American Nuclear Society, Hinsdale, Illinois, p. 276.