R. P. A. C. Newman (1993). “On the Structure of Conformal Singularities in Classical General Relativity”. 《Proc. R. Soc. Lond. A》 443 (1919): 473–492. Bibcode:1993RSPSA.443..473N. doi:10.1098/rspa.1993.0158.
R. P. A. C. Newman (1993). “On the Structure of Conformal Singularities in Classical General Relativity”. 《Proc. R. Soc. Lond. A》 443 (1919): 473–492. Bibcode:1993RSPSA.443..473N. doi:10.1098/rspa.1993.0158.