@article{GDZPPN00221914X, title = {Chapman's Classification of Shapes. A Proof Using Collapsing.}, journal = {Manuscripta mathematica}, volume = {17}, year = {1975}, pages = {373-384}, zbl = {0314.55012}, url = {http://dml.mathdoc.fr/item/GDZPPN00221914X} }
Siebenmann, Larry. Chapman's Classification of Shapes. A Proof Using Collapsing.. Manuscripta mathematica, Tome 17 (1975) pp. 373-384. http://gdmltest.u-ga.fr/item/GDZPPN00221914X/