Normality and Quotients in Crossed Modules and Group-groupoids

Combinatorial homotopy. I

J. H. C. Whitehead · Bulletin of the American Mathematical Society · 1949 · 848 citations · Full text

Natural Sciences, Mathematics, Combinatorics +9

Semi-abelian categories

George Janelidze, L. Márki, Walter Tholen · Journal of Pure and Applied Algebra · 2002 · 478 citations

Combinatorial homotopy. II

J. H. C. Whitehead · Bulletin of the American Mathematical Society · 1949 · 399 citations · Full text

Spaces with finitely many non-trivial homotopy groups

Jean-Louis Loday · Journal of Pure and Applied Algebra · 1982 · 323 citations

Natural Sciences, Mathematics, Topology +8

Higher Dimensional Algebra

John C. Baez, Martin Neuchl · Advances in Mathematics · 1996 · 269 citations