You can't add new quotations and references to the paper before the defense. When writing a paper, citing documents is an important part. Citing documents can support or prove your research, and it can also show what existing knowledge and research results your research is based on. When quoting files, you should operate strictly according to the specifications, and you can't add them at will. It is necessary to ensure that the cited documents are authentic, authoritative and credible, and conform to the theme and research direction of the paper. Therefore, you can't add new quotations and references to the thesis before the thesis defense.