Higher Order Commutators in Interpolation Theory. M.J. Carro, J. Cerda, J. Soria (1995) Mathematica Scandinavica
Hölder Classes with Boundary Conditions as Interpolation Spaces. Paolo Acquistapace, Brunello Terreni (1987) Mathematische Zeitschrift
Holomorphic semigroups in interpolation and extrapolation spaces. G. di Blasio (1993) Semigroup forum