1.
Salud pública Méx
; 24(3): 321-337, 1982.
Article
in Spanish
| LILACS
| ID: lil-9989
2.
Salud pública Méx
; 24(3): 329-340, 1982.
Article
in Spanish
| LILACS
| ID: lil-9990
3.
Gac. méd. Méx
; 117(1): 35-9, 1981.
Article
in Spanish
| LILACS
| ID: lil-6452