@article{10_1017_S0017089500006832,
     author = {Appleby, P. G. and Duffy, B. R. and Ogden, R. W.},
     title = {On the classification of isotropic tensors},
     journal = {Glasgow mathematical journal},
     pages = {185--196},
     year = {1987},
     volume = {29},
     number = {2},
     doi = {10.1017/S0017089500006832},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500006832/}
}