1. https://www.encyclopediaofmath.org//index.php?title=Kronecker_theorem.
2. https://www.mathworks.com/products/global-optimization.html.
3. Virtual Library of Simulation Experiments: Test Functions and Datasets. https://www.sfu.ca/%7Essurjano/optimization.html.
4. https://www.mat.univie.ac.at/ neum/software/mcs/.
5. http://www.glopt.net/softwares.html.