TY  - JOUR
AU  - M. M. Postnikov
TI  - Investigations in homotopy theory of continuous mappings. I.~The algebraic theory of systems. II.~The natural system and homotopy type
JO  - Trudy Matematicheskogo Instituta imeni V.A. Steklova
PY  - 1955
SP  - 3
EP  - 158
VL  - 46
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/TM_1955_46_a0/
LA  - ru
ID  - TM_1955_46_a0
ER  -