This paper illustrates the themes of the title in terms of: van Kampen type theorems for the fundamental groupoid; holonomy and monodromy groupoids; and higher homotopy groupoids. Interaction with work of the writer is explored.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-bc76-0-3, author = {Ronald Brown}, title = {Three themes in the work of Charles Ehresmann: local-to-global; groupoids; higher dimensions}, journal = {Banach Center Publications}, volume = {75}, year = {2007}, pages = {51-63}, zbl = {1123.01015}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-bc76-0-3} }
Ronald Brown. Three themes in the work of Charles Ehresmann: local-to-global; groupoids; higher dimensions. Banach Center Publications, Tome 75 (2007) pp. 51-63. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-bc76-0-3/