Grandis, Marco Directed algebraic topology. Models of non-reversible worlds. (English) Zbl 1176.55001 New Mathematical Monographs 13. Cambridge: Cambridge University Press (ISBN 978-0-521-76036-2/hbk). ix, 434 p. (2009). Reviewer: Hirokazu Nishimura (Tsukuba) MSC: 55-01 55U35 18D05 68Q85 PDF BibTeX XML Cite \textit{M. Grandis}, Directed algebraic topology. Models of non-reversible worlds. Cambridge: Cambridge University Press (2009; Zbl 1176.55001)
Ruiz Salguero, Carlos; Ruiz-Salguero, Roberto Kan’s condition and the notion of groupoid. (Spanish) Zbl 0256.18010 Rev. Colomb. Mat. 5, 59-82 (1971). MSC: 18G30 55U10 PDF BibTeX XML Cite \textit{C. Ruiz Salguero} and \textit{R. Ruiz-Salguero}, Rev. Colomb. Mat. 5, 59--82 (1971; Zbl 0256.18010) Full Text: EuDML
Kan, Daniel M. Abstract homotopy. IV. (English) Zbl 0071.16901 Proc. Natl. Acad. Sci. USA 42, 542-544 (1956). MSC: 55Pxx PDF BibTeX XML Cite \textit{D. M. Kan}, Proc. Natl. Acad. Sci. USA 42, 542--544 (1956; Zbl 0071.16901) Full Text: DOI