@article{MM3_2000_4_1_a11,
     author = {Miroslava Petrovi\'c-Torga\v{s}ev and Emilija \v{S}u\'curovi\'c},
     title = {Some {Characterization} of {Lorentzian} {Spherical} {Spacelike} {Curves} with the {Timelike} and the {Null} {Principal} {Normal}},
     journal = {Mathematica Moravica},
     pages = {83 - 92},
     publisher = {mathdoc},
     volume = {4},
     number = {1},
     year = {2000},
     url = {https://geodesic-test.mathdoc.fr/item/MM3_2000_4_1_a11/}
}