@article{10_4064_cm122_1_7,
     author = {Carlo Alberto Mantica and Luca Guido Molinari},
     title = {A second-order identity for the {Riemann} tensor and applications},
     journal = {Colloquium Mathematicum},
     pages = {69--82},
     publisher = {mathdoc},
     volume = {122},
     number = {1},
     year = {2011},
     doi = {10.4064/cm122-1-7},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm122-1-7/}
}