Meurant, Robert C. “Core–Shell and Core–Multi-Shell Configurations of the Polyhedra According to the Separation of Faces, and Their Interlayer Polytopes”. European Journal of Applied Sciences 11, no. 1 (January 22, 2023): 94–120. Accessed March 29, 2024. https://journals.scholarpublishing.org/index.php/AIVP/article/view/13783.