1:https://zhuanlan.zhihu.com/p/681629684
2:http://www.ad-cn.net/index.php?m=content&c=index&a=show&catid=7&id=539
3:https://zhuanlan.zhihu.com/p/144517613
4:http://www.ad-cn.net/index.php?m=content&c=index&a=show&catid=7&id=539
5:https://www.jinse.cn/blockchain/188573.html
6:http://www.baidu.com/link?url=7ccMIo_NXHM0XVexrq5aSza4PIKcgnh3UJoSs7fXRhbiglAyVL2wnfTJXpVM-zIku_q24m5wSXbd5vGbqNRXFQvzTt-KcTj7SQli_qNoUya
7:http://www.baidu.com/link?url=IdoqA_xzkcO7Gv_C5q3YXZFnEjgqRqNdM8yz2RrdKUgQkqp7aQqxosuzoyPXLfjSdYQHZ25SGid5SyeO_DeJhK
8:http://www.baidu.com/link?url=HHY5iYf4QG1sKrxFFBmX0eewGl7f7XlFCH8yKKRYiasrsm_qQsnCUCcmguA6i2mK80hnPTHENPVfQ4xDRNBoF_
9:http://www.baidu.com/link?url=d9yN9RfXFrDEbNp1H1KRl4xV6PbMmMmQZUBvkM6dL4hF-7EBN6kvBBLDcHw7K6Ke
10:http://www.baidu.com/link?url=ICrKQK06qnWAs55WtFQvz_B3QdHg3NEVSilnCZWVxrwofb9-w_M5vOkbOy4a_f2DX7r1HZyFxWo6bw6KMotU5K
11:https://www.sogou.com/link?url=hedJjaC291PpP0LsqQrO3lKaA-qsHOrpDahn4J4Fl-VJYAJ1CUY6hw..
12:http://qccdata.qichacha.com/ReportData/PDF/950c9a43397d337ae547f0026147f06a.pdf
13:https://www.hanspub.org/journal/PaperInformation.aspx?paperID=29079
14:https://www.jsjkx.com/CN/article/openArticlePDF.jsp?id=18147
15:https://zhuanlan.zhihu.com/p/258757075
16:http://www.baidu.com/link?url=d9yN9RfXFrDEbNp1H1KRlHCg5gPyWPLKxEIDA_uvbOrzq12fXbCwB5PN28zO-9fR
17:https://www.infoq.cn/article/euwssc9dhwlih2iyusg2
18:https://www.mbalib.com/ask/question-cbbb32cf1a351ff618cbdfff9a6faf9e.html
19:https://www.sogou.com/link?url=hedJjaC291NbWrwHYHKCyPQj_ei8OKC13fJZ5YRQyvgzW7xP33j8cc5Jmx_P2exo0ztd7q5nl6o.