Persistence of undercompressive phase boundaries for isothermal Euler equations including configurational forces and surface tension. Math. Meth. Appl. Sci., (39)18:5409--5426, 2016. [PUMA: liquid-vapor stability, interface, adjoint symmetrizer, energy problem condition, uniform linearized estimate, well-posedness, Kreiss vorlaeufig Kreiss�Lopatinskii?] URL