no. 2
Existence and non-existence results for harmonic maps between spheres
Annali della Scuola Normale Superiore di Pisa - Classe di Scienze, Série 4, Tome 17 (1990) no. 2, pp. 273-282. 
@article{ASNSP_1990_4_17_2_273_0,
     author = {Pettinati, Valter and Ratto, Andrea},
     title = {Existence and non-existence results for harmonic maps between spheres},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {273--282},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 17},
     number = {2},
     year = {1990},
     zbl = {0718.58017},
     mrnumber = {1076254},
     language = {en},
     url = {archive.numdam.org/item/ASNSP_1990_4_17_2_273_0/}
}
Pettinati, Valter; Ratto, Andrea. Existence and non-existence results for harmonic maps between spheres. Annali della Scuola Normale Superiore di Pisa - Classe di Scienze, Série 4, Tome 17 (1990) no. 2, pp. 273-282. http://archive.numdam.org/item/ASNSP_1990_4_17_2_273_0/

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