[1] SGMLguid - Wikipedia () <https://en.wikipedia.org/wiki/SGMLguid>
[2] Re: The Origin of Blockquote (Liam R. E. Quin著, ) <https://lists.w3.org/Archives/Public/public-webhistory/2017Aug/0002.html>
[3] Re: Provenance of the blockquote element (Dan Connolly著, ) <https://lists.w3.org/Archives/Public/public-webhistory/2017Sep/0000.html>