I am sorry for coming back to the topic but apparently, it seems that I have to make an important compromise by using BibTex.
If I choose your solution, while Unicode appears perfectly, the BibTex file does not download important information of the reference as the abstract or the Reviewed Item.
It really troubles me why Endnote faces such a problem with UTF-8 encoding. At the moment, I try to test all the import methods for RIS, but it seems in vain.
Thank you!