- 
              
            811
- 
              
            812World trends in contraceptive use, by method, and their relationship to fertilityĐược phát hành 1988Sách
- 
              
            813
- 
              
            814
- 
              
            815
- 
              
            816Sexually transmitted diseases and fertility a case study of Mahalapye subdistrict, Botswana.Được phát hành 1988Sách
- 
              
            817World trends in contraceptive use, by method, and their relationships to fertilityĐược phát hành 1988Sách
- 
              
            818
- 
              
            819
- 
              
            820