@article {1987, title = {Extensions of Lie superalgebras and supersymmetric Abelian gauge fields.}, journal = {Phys. Lett. B 193 (1987), no. 1, 61-66.}, number = {SISSA;26/87/FM}, year = {1987}, publisher = {SISSA Library}, doi = {10.1016/0370-2693(87)90456-4}, url = {http://hdl.handle.net/1963/507}, author = {Giovanni Landi and Giuseppe Marmo} }