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Mo - Mentor Graphics Technotes are found on our SupportNet site. As Yanfeng points out below, only customers with an active support contract can access TechNotes, AppNotes, the latest product versions, license keys and other info on SupportNet. If you are interested in getting information on renewing your support contract, please call our customer support at 1-800-547-4303, or find other ways to contact us and worldwide offices here: Mentor Graphics SupportNet.
This site is our Mentor Graphics communities site, and lots of customers are active on this site. so frequently contributors will put a link in a discussion post about a resource that can be found on SupportNet by our active support customers.
Thanks for your question.