The volumes have been published from 1980 to 1984 as Supplements to the
"Cahiers de Topologie et Géométrie Différentielle Catégoriques"
They are devoted to the collected works of the mathematician Charles Ehresmann (1905-1979), who created the Cahiers in 1958. They consist of 7 books, edited and commented by Andrée C. Ehresmann, and they contain all the articles de C. Ehresmann, with long comments (in English) updating the papers.
The pdf files of these volumes can be freely downloaded hereafter.
Part I (1 volume, 630 pages): Topologie Algébrique et Géométrie Différentielle
Part II (2 volumes, 800 pages): Structures locales et catégories ordonnées
II.1: Structures locales
II.2: Catégories ordonnées; Applications en Topologie
Part III (2 volumes, 900 pages): Catégories internes et Fibrations
Part IV (2 volumes, 850 pages): Esquisses, Complétions, Enrichissements
IV.1: Esquisses et Complétions