@article{GDZPPN002060892,
title = {Trees of Homotopy Types of Two-Dimensional CW-Complexes},
journal = {Commentarii mathematici Helvetici},
volume = {48},
year = {1973},
pages = {31-44},
zbl = {0262.55014},
url = {http://dml.mathdoc.fr/item/GDZPPN002060892}
}
Sieradski, Allan J.; Dyer, Michael N. Trees of Homotopy Types of Two-Dimensional CW-Complexes. Commentarii mathematici Helvetici, Tome 48 (1973) pp. 31-44. http://gdmltest.u-ga.fr/item/GDZPPN002060892/