Media type: E-Article Title: Lecture Notes in Mathematics: Groupoids and classification sequences Contributor: Heath, Philip R.; Kamps, Klaus Heiner imprint: Springer Berlin Heidelberg, 1979 Published in: Lecture Notes in Mathematics Language: Not determined DOI: 10.1007/bfb0065264 ISSN: 0075-8434; 1617-9692 Origination: Footnote: