@article{TAC_2010_24_a5,
     author = {Jonathon Funk and Pieter Hofstra},
     title = {Topos theoretic aspects of semigroup actions},
     journal = {Theory and applications of categories},
     pages = {117--147},
     publisher = {mathdoc},
     volume = {24},
     year = {2010},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TAC_2010_24_a5/}
}