Reyes, Armando, and Fabio Calderón. “Some Interactions Between Hopf Galois Extensions and Noncommutative Rings”. Universitas Scientiarum 27, no. 2 (August 10, 2022): 58–161. Accessed April 25, 2024. https://revistas.javeriana.edu.co/index.php/scientarium/article/view/33551.