@article{10_4153_CJM_1968_145_5,
     author = {Block, Richard E.},
     title = {On the {Extensions} of {Lie} {Algebras}},
     journal = {Canadian journal of mathematics},
     pages = {1439--1450},
     year = {1968},
     volume = {20},
     number = {1},
     doi = {10.4153/CJM-1968-145-5},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1968-145-5/}
}