@article{SIGMA_2017_13_a63,
     author = {Chi Zhang and Hua-Lin Huang},
     title = {A {Generalization} of the {Doubling} {Construction} for {Sums} of {Squares} {Identities}},
     journal = {Symmetry, integrability and geometry: methods and applications},
     year = {2017},
     volume = {13},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SIGMA_2017_13_a63/}
}