0121-0807 0121-0807 S0121-08072018000200174 10.18273/revsal.v50n2-2018011 Colombia Colombia Colombia Colombia Colombia 00 06 2018 00 06 2018 50 2 174 175 1. 2017 49 3 3 450-7 2. 3. 1971 4. 5. 2017 6. 7. 2010 30 1 1 5-9