The existence of nonzero solutions for a class of variational inequalities by index. - Yisheng Lai; Yuanguo Zhu; Yinbing Deng (Appl. Math. Lett., 2003)

Fixed point index approach for solutions of variational inequalities. - Yisheng Lai; Yuanguo Zhu; Yinbing Deng (Int. J. Math. Math. Sci., 2005)