@article{10_4064_fm_135_2_111_126,
     author = {B. Wehrfritz},
     title = {The upper central series of some matrix groups},
     journal = {Fundamenta Mathematicae},
     pages = {111--126},
     publisher = {mathdoc},
     volume = {135},
     number = {2},
     year = {1990},
     doi = {10.4064/fm-135-2-111-126},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm-135-2-111-126/}
}