@article{1103841120, author = {Zimmerman, Wolfhart}, title = {Direction-dependent singularities for $A^{4}$-coupling}, journal = {Comm. Math. Phys.}, volume = {7}, number = {1}, year = {1968}, pages = { 325-329}, language = {en}, url = {http://dml.mathdoc.fr/item/1103841120} }
Zimmerman, Wolfhart. Direction-dependent singularities for $A^{4}$-coupling. Comm. Math. Phys., Tome 7 (1968) no. 1, pp. 325-329. http://gdmltest.u-ga.fr/item/1103841120/