1.
Article
in English
| WHO IRIS
| ID: who-48671
2.
Article
in French
| WHO IRIS
| ID: who-45944
3.
Article
in Spanish
| WHO IRIS
| ID: who-45342
4.
World Health Forum (WHO)
; 7(4): 380-87, 1986.
Article
in English
| PAHO
| ID: pah-14639