Geroch, Robert (1968), “Spinor Structure of Space-Times in General Relativity. I”, 《Journal of Mathematical Physics》 9 (11): 1739–1743, Bibcode:1968JMP.....9.1739G, doi:10.1063/1.1664507
Parker, Phillip E. (1984), “On some theorems of Geroch and Stiefel”, 《Journal of Mathematical Physics》 25 (3): 597–599, doi:10.1063/1.1665067
harvard.edu
adsabs.harvard.edu
Geroch, Robert (1968), “Spinor Structure of Space-Times in General Relativity. I”, 《Journal of Mathematical Physics》 9 (11): 1739–1743, Bibcode:1968JMP.....9.1739G, doi:10.1063/1.1664507