何伟的文章：The Peace Corps Breaks Ties with China by Peter Hessler
https://www.newyorker.com/magazine/2020/03/16/the-peace-corps-breaks-ties-with-china
美中友好志愿者2016年度报告
https://s3.amazonaws.com/files.peacecorps.gov/documents/2016_Annual_Report.pdf
美中友好志愿者2018 年度报告
https://s3.amazonaws.com/files.peacecorps.gov/documents/ANNUAL_REPORT_2018_PDF.pdf