@article{PDA_1983_12_a2, author = {I. Lukav\v{c}evi\'c}, title = {The {World} {Lines} of {Isotropic} {Expansion} in the {De} {Sitter} {Universe}}, journal = {Publications of the Department of Astronomy}, pages = {19 }, publisher = {mathdoc}, volume = {12}, year = {1983}, language = {en}, url = {http://geodesic.mathdoc.fr/item/PDA_1983_12_a2/} }