Ccolque Taipe, Felipe Clímaco. “ Chain Contracting Homotopy and a Method for Relative Projective Resolutions”. Selecciones Matemáticas 9, no. 01 (July 27, 2022): 102 - 120. Accessed June 12, 2024. https://revistas.unitru.edu.pe/index.php/SSMM/article/view/3895.