TY - JOUR AU - Allan J. Sieradski AU - Michael N. Dyer TI - Trees of Homotopy Types of Two-Dimensional CW-Complexes JO - Commentarii mathematici Helvetici PY - 1973 SP - 31 EP - 44 VL - 48 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/CMH_1973__48_139535/ ID - CMH_1973__48_139535 ER -