@article{GDZPPN00222108X,
title = {The Elements of K2 (...s).},
journal = {Manuscripta mathematica},
volume = {25},
year = {1978},
pages = {173-178},
zbl = {0374.13009},
url = {http://dml.mathdoc.fr/item/GDZPPN00222108X}
}
Hurrelbrink, Jürgen. The Elements of K2 (...s).. Manuscripta mathematica, Tome 25 (1978) pp. 173-178. http://gdmltest.u-ga.fr/item/GDZPPN00222108X/