Internal Categories and Groupoids in Congruence Modular Varieties

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

Ralph Freese and Ralph McKenzie. Commutator theory for congruence modular varieties. London Mathematical Society lecture note series, no. 125. Cambridge University Press, Cambridge etc. 1987, iii + 227 pp.

Matthew Valeriote · Journal of Symbolic Logic · 1989 · 309 citations

Natural Sciences, Mathematics, Number Theory +9

G-groupoids, crossed modules and the fundamental groupoid of a topological group

Ronald Brown, Christopher B. Spencer · Indagationes Mathematicae (Proceedings) · 1976 · 224 citations

Natural Sciences, Mathematics, Geometry +12

Galois theory and a general notion of central extension

George Janelidze, G. M. Kelly · Journal of Pure and Applied Algebra · 1994 · 151 citations

Natural Sciences, Mathematics, Algebra +9

A Categorical Approach to Commutator Theory

Maria Cristina Pedicchio · Journal of Algebra · 1995 · 108 citations

Natural Sciences, Mathematics, Physics +14