1. Acerbi E., Mingione G.: Gradient estimates for a class of parabolic systems. Duke Math. J. 136, 285–320 (2007)
2. Adams D.R.: Traces of potentials arising from translation invariant operators. Ann. Scuola Norm. Sup. Pisa Cl. Sci. 25(3), 203–217 (1971)
3. Adams D.R.: A note on Riesz potentials. Duke Math. J. 42, 765–778 (1975)
4. Adams, D.R.: Lectures on L p -potential theory. Department of Mathematics, University of Umea (1981)
5. Adams D.R., Hedberg L.I.: Function Spaces and Potential Theory. Grundlehren der Mathematischen Wissenschaften 314. Springer-Verlag, Berlin (1996)