2616-7964 2616-7964 S2616-79642021000300723 10.33996/revistahorizontes.v5i19.232 Bolivia 00 09 2021 00 09 2021 5 19 723 732

1983 2001 2004 1 1 1 14-26. 1999 1988 78 7 7 674-81 2006 1996 1999 2002 40 2 2 2006