@article{GDZPPN002023911, title = {Divergence-Free Tensorial Concomitants.}, journal = {Aequationes mathematicae}, volume = {5}, year = {1970}, pages = {127-138}, zbl = {0193.50602}, url = {http://dml.mathdoc.fr/item/GDZPPN002023911} }
Lovelock, David. Divergence-Free Tensorial Concomitants.. Aequationes mathematicae, Tome 5 (1970) pp. 127-138. http://gdmltest.u-ga.fr/item/GDZPPN002023911/