Juan Jos Salazar Gonzlez <jjsalaza@ull.es>
For his help explaining his method of solving CSP problem
Andrew Makhorin <mao@gnu.org>
For his help in the use of GLPK's callback function
Chris Matrakidis <cmatraki@gmail.com> and Heinrich Schuchardt <xypron.glpk@gmx.de>
For their help when we migrate from GLPK v4.47 to v.60 
	
