@article{PIM_1979_N_S_25_39_a19,
     author = {Vojislav Petrovi\'c},
     title = {Product-Concircular {Curvature} {Tensor}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {131 },
     publisher = {mathdoc},
     volume = {_N_S_25},
     number = {39},
     year = {1979},
     url = {http://geodesic.mathdoc.fr/item/PIM_1979_N_S_25_39_a19/}
}