Mapping a group to the corresponding groupoid with one object is sometimes called delooping, especially in the context of homotopy theory, see delooping in nLab. ncatlab.org. [2017-10-31]. (原始内容存档于2023-04-05)..
Mapping a group to the corresponding groupoid with one object is sometimes called delooping, especially in the context of homotopy theory, see delooping in nLab. ncatlab.org. [2017-10-31]. (原始内容存档于2023-04-05)..
Ehresmann, Charles. Catégories et structures : extraits. Séminaire Ehresmann. Topologie et géométrie différentielle. 1964, 6: 1–31 [2023-11-29]. (原始内容存档于2023-06-04) (英语).