1
2
3
Published in 1984
Repository
4
Published in 2001
Repository
5
6
Published in 1986
Repository
7
8
9
10
Published in 2010
Repository
11
12
13
article
Published in 2000
Repository Repositorio SENESCYT
14
Published in 1991
Repository
15
16
Published in 2000
Repository
17
18
Published in 1998
Repository
19
20
Published in 2010
Repository