Research on several problems of emigrant workers in China Housing problems of migrant workers in China Housing problems of migrant workers in China. Research on social protection and citizenization of migrant workers in China Research on several problems about cultivation of small city new generation migrant workers in China 并列题名：Research on social protection and citizenization of migrant workers in China 并列题名：Study on self-employment behavior of migrant workers in China Study on self-employment behavior of migrant workers in China Research on the quantity and composition of migrant workers' grain demand in China