Tetrahedron - Math bibliographies - in Harvard style

In-text: (Elgersma, 2016)

Your Bibliography: Elgersma, M., 2016. The Quadrahelix: A Nearly Perfect Loop of Tetrahedra. [online] Arxiv.org. Available at: <https://arxiv.org/ftp/arxiv/papers/1610/1610.00280.pdf> [Accessed 7 December 2020].

In-text: (Hayes, 2012)

Your Bibliography: Hayes, B., 2012. The Science of Sticky Spheres. American Scientist, [online] 101(1), p.3. Available at: <https://www.americanscientist.org/article/tetrahedral-tetris#> [Accessed 7 December 2020].

In-text: (Boerdijk–Coxeter helix | Wikiwand, 2020)

Your Bibliography: Wikiwand. 2020. Boerdijk–Coxeter helix | Wikiwand. [online] Available at: <https://www.wikiwand.com/en/Boerdijk%E2%80%93Coxeter_helix> [Accessed 7 December 2020].