Sharp borderline Sobolev inequalities on compact Riemannian manifolds. Luigi Fontana — 1993 Commentarii mathematici Helvetici
Hodge theory in the Sobolev topology for the de Rham complex on a smoothly bounded domain in Euclidean space. Fontana, Luigi; Krantz, Steven G.; Peloso, Marco M. — 1995 Electronic Research Announcements of the American Mathematical Society [electronic only]