The next references are advised to better assimilate the contents of the course. Apart from the handouts by the teacher, the other book-references can be considered "not essential":
Afternotes by the teacher, available at https://moodle.unive.it/
M.S.Bazaraa, H.D.Sherali, C.M.Shetty (1993) "Nonlinear Programming - Theory and Algorithms (2nd edition), John Wiley & Sons.
D.P.Bertsekas (1982) "Constrained Optimization and Lagrange Multiplier Methods", Academic Press.
D.P.Bertsekas (1995) "Nonlinear Programming", Athena Scientific, Belmont, Massachusetts, USA.
R.Walter (1976) "Principles of Mathematical Analysis", McGraw-Hill.
C.H.Edwards, “Advanced Calculus of Several Variables”, Dover Publications, 2003
B.T.M. Apostol “Calculus: Multivariable Calculus and Linear Algebra, with Applications to Differential Equations and Probability, vol. II, Second Edition”, John Wiley and Sons, Inc., 1973
J.Nocedal, S.J.Wright, “Numerical Optimization, Second Edition”, Springer, 2006.
S.Boyd, L.Vandenberghe “Convex Optimization”, Cambridge University Press, 2009.