1. Sopra alcune questioni di elastostatica;Signorini,1933
2. The linear theory of elasticity;Gurtin,1972
3. Les Inéquations en Mécanique et en Physique;Duvaut,1972
4. Contact Problems in the Classical Theory of Elasticity;Gladwell,1980
5. Inequality Problems in Mechanics and Applications;Panagiotopoulos,1985