1:https://finance.sina.com.cn/money/future/fmnews/2021-04-07/doc-ikmxzfmk5499424.shtml
2:http://www.xinhuanet.com/science/2022-08/25/c_1310655767.htm
3:https://zhuanlan.zhihu.com/p/473213742
4:https://www.reportsworld.cn/reports/221198-molded-plastic-market-report.html
5:https://www.zhihu.com/market/pub/120054708/manuscript/1289626852106579968