 W. Arendt and K. Urban,
Partielle Differenzialgleichungen,
Spektrum Akademischer Verlag, 2010
 L. C. Evans, Partial differential equations, Graduate Studies in Mathematics Vol. 19, AMS, 1998
 G. Grubb, Distributions and operators, Graduate Texts in Mathematics Vol. 252, Springer, 2009.
 D. Haroske and H. Triebel, Distributions, Sobolev Spaces, elliptic equations, EMS Textbooks in Mathematics, 2008
 W. McLean, Strongly elliptic systems and boundary integral equations, Cambridge University Press, Cambridge, 2000.
