@misc{bateman_2018_1447802, author = {Bateman, H.}, title = {{The Conformal Transformations of a Space of Four Dimensions and Their Applications to Geometrical Optics}}, month = oct, year = 2018, publisher = {Zenodo}, doi = {10.1112/plms/s2-7.1.70}, url = {https://doi.org/10.1112/plms/s2-7.1.70} }