0121-0807 0121-0807 S0121-08072018000200170 10.18273/revsal.v50n2-2018009 Colombia Colombia 00 06 2018 00 06 2018 50 2 170 171 1. 1994 84 1 2. 1808 29 262-3 3. 1808 30 264-6 4. 2010 12 3 3 474-85 5. 2006 1-10 6. 2002 7. 2008 28 4 4 480-96 8. 1978 56 3 3 403-16