TY  - JOUR
AU  - Graham Ellis
TI  - Crossed squares and combinatorical homotopy.
JO  - Mathematische Zeitschrift
PY  - 1993
SP  - 93
EP  - 110
VL  - 214
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MZ_1993__214_1_174557/
ID  - MZ_1993__214_1_174557
ER  -