1.
Rev. Univ. Guayaquil
;
77(3): 181-92, jul.-sept. 1989. mapas, ilus
Article
in Spanish
| LILACS
| ID: lil-83745
2.
Rev. Univ. Guayaquil
;
74(4): 61-73, oct.-dic. 1988. ilus, tab
Article
in Spanish
| LILACS
| ID: lil-75536