Uniqueness of the polar factorisation and projection of a vector-valued mapping

Burton, G. R.; Douglas, R. J.

Annales de l'I.H.P. Analyse non linéaire, Volume 20 (2003) p. 405-418

Variational problems on classes of rearrangements and multiple configurations for steady vortices

Burton, G. R.

Annales de l'I.H.P. Analyse non linéaire, Volume 6 (1989) p. 295-319