1. Standard ISO/TC 60 - Gears, Technical Committee: ISO/TC 60 Gears www.iso.org/committee/49212.html.
2. Standard ISO 54:1996 - Cylindrical gears for general engineering and for heavy engineering - Modules, Technical Committee: ISO/TC 60 Gears.
3. Standard JIS B 1701-2:2017 - Cylindrical Gears For General Engineering And For Heavy Engineering - Part 2: Module, Technical Committee: Japanese Standards Association.
4. Shaper Cutters – Brochure, SampUtensili, Shaper_cutter_en_v.06.00, www.samputensil.com, https://pdf.directindustry.com/pdf/samputensili/shaper-cutters/33463-23714.html
5. Solid-Steel and Carbide Hobs – Brochure, SampUtensili, Hobs_en_v.07.00, www.samputensil.com, https://pdf.directindustry.com/pdf/samputensili/solid-steel-carbide-hobs/33463-23711.html,