@article{10_2298_PIM0795003C,
     author = {Sini\v{s}a Crvenkovi\'c and Vladimir Tasi\'c},
     title = {Second cohomology and nilpotency class 2},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {3 },
     publisher = {mathdoc},
     volume = {_N_S_81},
     number = {95},
     year = {2007},
     doi = {10.2298/PIM0795003C},
     zbl = {1186.20034},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.2298/PIM0795003C/}
}