Gaya APA

Yang, R. et al (1989). The Risk Approach in Perinatal Health Shunyi County, People Republic of China . Atlanta: US.Department of Health and Human Services.

Gaya MLA

Yang, Ren-Ying. et al. "The Risk Approach in Perinatal Health Shunyi County, People Republic of China". Atlanta: US.Department of Health and Human Services, 1989. print.