History of the Northern Dynasties, fifteenth of the 24 dynastic histories 二十四史[èr shí sì shǐ], compiled by Li Yanshou 李延寿[lǐ yán shòu] in 659 during Tang Dynasty, 100 scrolls
1.to migrate to Beijing or Taipei in search of better job opportunities2.migrant worker living and working in Beijing or Taipei without a residence permit
"Beijing cough", respiratory problems caused by dry and polluted Beijing air, typically experienced by non-acclimated foreigners who would otherwise have no such problems