@article{AIHPC_1989__6_6_503_0,
     author = {Ratto, Andrea},
     title = {Equivariant harmonic maps between manifolds with metrics of $(p, q)$-signature},
     journal = {Annales de l'I.H.P. Analyse non lin\'eaire},
     pages = {503--524},
     publisher = {Gauthier-Villars},
     volume = {6},
     number = {6},
     year = {1989},
     mrnumber = {1035340},
     zbl = {0703.58015},
     language = {en},
     url = {http://www.numdam.org/item/AIHPC_1989__6_6_503_0/}
}