@article{JRAM_1964__213_150593,
     author = {Leon Bernstein},
     title = {Periodicity of {Jacobi's} {Algorithm} for a special type of {Cubic} {Irrationals.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {137--146},
     publisher = {mathdoc},
     volume = {213},
     year = {1964},
     zbl = {0121.05201},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1964__213_150593/}
}