A generalization of Signorini's perturbation method suggested by two problems of Grioli
Rendiconti del Seminario Matematico della Università di Padova, Tome 68 (1982) , pp. 149-162. 
@article{RSMUP_1982__68__149_0,
     author = {Capriz, Gianfranco and Podio-Guidugli, P.},
     title = {A generalization of Signorini's perturbation method suggested by two problems of Grioli},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {149--162},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {68},
     year = {1982},
     zbl = {0509.73016},
     mrnumber = {702153},
     language = {en},
     url = {www.numdam.org/item/RSMUP_1982__68__149_0/}
}
Capriz, G.; Podio-Guidugli, P. A generalization of Signorini's perturbation method suggested by two problems of Grioli. Rendiconti del Seminario Matematico della Università di Padova, Tome 68 (1982) , pp. 149-162. http://www.numdam.org/item/RSMUP_1982__68__149_0/

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