Textbooks

• L.C. Evans Partial Differential Equations American Mathematical Society 2nd ed (2010)
• S. Salsa - Partial Differential Equations in Action - Springer 3rd ed. (2016)
• Q.Han - A Basic course in Partial Differential Equations Graduate Studies in Mathematics vol. 120 AMS (2010)
• D. Gilbarg, N.S. Trudinger - Elliptic PDEs of second order Springer Verlag (1983)
• G.B. Folland - An introduction to PDEs Princeton Univ. Press (1976)
• Ya-Zhe Chen, Lan-Cheng Wu - Second order Elliptic Equations and Elliptic Systems Translation of Mathematical Monographs vol.174, AMS (1998)