英媒：榨菜 - 开包即食的治国小菜 (UK media: “Pickle Index” shows trends of migrant workers)
British Broadcasting Corporation, August 14, 2013
http://www.bbc.co.uk/zhongwen/simp/press_review/2013/08/130814_press_china_zhacai.shtml
Related:
"Pickle index" measures changing tide of Chinese migrant workers
South China Morning Post, August 14, 2013
http://www.scmp.com/news/china-insider/article/1296315/pickle-index-measures-chinese-worker-migration