no. 4
On the coincidence set in biharmonic variational inequalities with thin obstacles
Annali della Scuola Normale Superiore di Pisa - Classe di Scienze, Série 4, Tome 13 (1986) no. 4, pp. 559-616. 
@article{ASNSP_1986_4_13_4_559_0,
     author = {Schild, Bernhard},
     title = {On the coincidence set in biharmonic variational inequalities with thin obstacles},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {559--616},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 13},
     number = {4},
     year = {1986},
     zbl = {0704.35055},
     mrnumber = {880399},
     language = {en},
     url = {www.numdam.org/item/ASNSP_1986_4_13_4_559_0/}
}
Schild, Bernhard. On the coincidence set in biharmonic variational inequalities with thin obstacles. Annali della Scuola Normale Superiore di Pisa - Classe di Scienze, Série 4, Tome 13 (1986) no. 4, pp. 559-616. http://www.numdam.org/item/ASNSP_1986_4_13_4_559_0/

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