Send the following on WhatsApp
Continue to ChatBertrand Offsets of Ruled Surfaces with Darboux Frame - https://avesis.yildiz.edu.tr/yayin/2d37b563-efc7-42ac-b079-1795f9e4dce9/bertrand-offsets-of-ruled-surfaces-with-darboux-frame
Bertrand Offsets of Ruled Surfaces with Darboux Frame - https://avesis.yildiz.edu.tr/yayin/2d37b563-efc7-42ac-b079-1795f9e4dce9/bertrand-offsets-of-ruled-surfaces-with-darboux-frame