1. F.J. Almgren, Jr., Homotopy groups of the integral cycle groups, Topology
1 (1962), 257–299.
2. M.F. Atiyah, J.D. Jones, Topological aspects of Yang-Mills theory, Comm. Math.Phys.
61 (1978), 97–118.
3. A. Bahri, Critical Points at Infinity in Some Variational Problems, Pitman Res. Notes Math. Ser. 182, Harlow, 1989.
4. R.J. Baston and M.G Eastwood, The Penrose Transform,Oxford University Press,1989.
5. C.P. Boyer, J. Hurtubise, B.M. Mann, R.J. Milgram, The topology of instanton moduli spaces. I: The Atiyah-Jones conjecture,Ann.of Math
137 (1993), 561–609.