@article{TAM_1984_10_1_a10,
     author = {Dragi Radojevi\'c},
     title = {Expansion tensor in the metrics of {Einstein} and {Schwarzschild}},
     journal = {Theoretical and applied mechanics},
     pages = {113 },
     year = {1984},
     volume = {10},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TAM_1984_10_1_a10/}
}