1. Friedman, A., Hu Bei, A Stefan Problem for a protocell model, SIAM J. Math. Anal., 1998, 30: 912–926.
2. Schwegler, H., Tarumi, K., Gerstmann, B., Physico-chemical model of protocell, J. Math. Biology, 1995, 22: 335–348.
3. Tarumi, K., Schwegler, H., A nonlinear treatment of the protocell by boundary layer approximation, Bull. Math. Biology, 1987, 49: 307–320.
4. Wang Xiaohua, Yi Fahuai, Local classical solution of a multidimensional free boundary problem, to appear on Acta Math. Scientia.
5. Rodrigues, J. F., Obstacle Problems in Mathematical Physics, Amsterdam: North-Holland, Elsevier Science Publishers B. V., 1987.