Walker, Marshall Homotopy pullbacks and the Hopf invariant. (English) Zbl 0407.55015 J. Lond. Math. Soc., II. Ser. 19, 153-155 (1979). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 1 ReviewCited in 3 Documents MSC: 55Q25 Hopf invariants 55Q05 Homotopy groups, general; sets of homotopy classes Keywords:Homotopy Pullback; Homotopy Pushout; Hopf Invariant; Ehp Sequence PDF BibTeX XML Cite \textit{M. Walker}, J. Lond. Math. Soc., II. Ser. 19, 153--155 (1979; Zbl 0407.55015) Full Text: DOI OpenURL