1. Fujita, H.: Flow Problems with Unilateral Boundary Conditions. Lecons, Collège de France (1993)
2. Fujita, H., Kawarada, H.: Variational inequalities for the Stokes equation with boundary conditions of friction type. Recent Dev. Domain Decompos. Methods Flow Probl. 11, 15–33 (1998)
3. Fujita, H.: A mathematical analysis of motions of viscous incompressible fluid under leak or slip boundary conditions. RIMS Kokyuroku 888, 199–216 (1994)
4. Fujita, H.: Non-stationary Stokes flows under leak boundary conditions of friction type. J. Comput. Math. 19, 1–8 (2001)
5. Fujita, H.: A coherent analysis of Stokes flows under boundary conditions of friction type. J. Comput. Appl. Math. 149, 57–69 (2002)