This marquadt test example was provided by
    https://www.gnu.org/software/gsl/doc/html/nls.html
and copyright per usual GNU Software Library standards.

The bspline code example is #3, found at
    https://www.gnu.org/software/gsl/doc/html/bspline.html

The minimizer example comes from the first Example of
    https://www.gnu.org/software/gsl/doc/html/min.html

All of this is covered by the usual GNU Software Library,
i.e. GNU General Public License, and the HTML pages are
copyright 1996-2024 by the GSL Team.
