Stephen Hawking wrote 1999: So what the singularity theorems are really telling us, is that the universe had a quantum origin, and that we need a theory of quantum cosmology, if we are to predict the present state of the universe.“Quantum Cosmology, M-theory and the Anthropic Principle - Stephen Hawking”. 2015년 2월 14일에 원본 문서에서 보존된 문서. 2015년 2월 14일에 확인함.
Stephen Hawking wrote 1999: So what the singularity theorems are really telling us, is that the universe had a quantum origin, and that we need a theory of quantum cosmology, if we are to predict the present state of the universe.“Quantum Cosmology, M-theory and the Anthropic Principle - Stephen Hawking”. 2015년 2월 14일에 원본 문서에서 보존된 문서. 2015년 2월 14일에 확인함.