@article{10_4064_sm150_1_2,
     author = {Paul F. X. M\"uller},
     title = {A simplification in the proof of the non-isomorphism
 between $H^1(\delta )$ and $H^1(\delta ^2)$},
     journal = {Studia Mathematica},
     pages = {13--16},
     year = {2002},
     volume = {150},
     number = {1},
     doi = {10.4064/sm150-1-2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm150-1-2/}
}