K. Schittkowski (2002): Numerical Data Fitting in Dynamical Systems - A Practical Introduction with Applications and Software, Kluwer Academic Publishers

H. Hörnlein, K. Schittkowski eds. (1992): Software Systems for Structural Optimization, International Series of Numerical Mathematics, Vol. 110, Birkhäuser

K. Schittkowski (1987): More Test Examples for Nonlinear Programming, Lecture Notes in Economics and Mathematical Systems, Vol. 282, Springer

K. Schittkowski ed. (1985): Computational Mathematical Programming, NATO ASI Series F: Computer and Systems Sciences, Vol. 15, Springer 

W. Hock, K. Schittkowski (1981): Test Examples for Nonlinear Programming Codes, Lecture Notes in Economics and Mathematical Systems, Vol. 187, Springer
... out of print

K. Schittkowski (1980): Nonlinear Programming Codes - Information, Tests, Performance, Lecture Notes in Economics and Mathematical Systems, Vol. 183, Springer
... out of print