On the Uniqueness of Capillary Surfaces without Gravity over an Infinite Strip Luen-Fai Tam Indiana University Mathematics Journal 1987 text pdf 10.1512/iumj.1987.36.36004 10.1512/iumj.1987.36.36004 en Indiana Univ. Math. J. 36 (1987) 79 - 89 state-of-the-art mathematics http://iumj.org/access/