@article{01770074,
title = {Secondary cohomology and the Steenrod square.},
journal = {Homology, Homotopy and Applications},
volume = {4},
year = {2002},
pages = {29-62},
zbl = {0996.55005},
language = {en},
url = {http://dml.mathdoc.fr/item/01770074}
}
Baues, Hans-Joachim. Secondary cohomology and the Steenrod square.. Homology, Homotopy and Applications, Tome 4 (2002) pp. 29-62. http://gdmltest.u-ga.fr/item/01770074/