Source: https://www.researchgate.net/profile/Changki-Mo/publication/316230149_3D_Printed_Thermoplastic_Polyurethane_with_Isotropic_Material_Properties/links/5a564db00f7e9bf2a536c13c/3D-Printed-Thermoplastic-Polyurethane-with-Isotropic-Material-Properties.pdf