
O. Exler, K. Schittkowksi
(2007): A trust region SQP algorithm for
mixedinteger nonlinear programming, Optimization Letters, Vol. 1,
269280 

O. Exler, T. Lehmann, K. Schittkowski (2012):
MISQP: A Fortran subroutine
of a trust region SQP algorithm for mixedinteger nonlinear
programming  user's guide, Report, Department of Computer
Science, University of Bayreuth 

O. Exler, K. Schittkowski, T. Lehmann (2012):
A comparative study of
numerical algorithms for nonlinear and nonconvex mixedinteger
optimization, to appear: Mathematical Programming Computation 