@article{1103899759, author = {Clarke, C. J. S.}, title = {On the four-valuedness of twistors}, journal = {Comm. Math. Phys.}, volume = {46}, number = {1}, year = {1976}, pages = { 229-231}, language = {en}, url = {http://dml.mathdoc.fr/item/1103899759} }
Clarke, C. J. S. On the four-valuedness of twistors. Comm. Math. Phys., Tome 46 (1976) no. 1, pp. 229-231. http://gdmltest.u-ga.fr/item/1103899759/