1390-0129 1390-0129 S1390-01292019000500043 10.33333/rp.vol44n2.05 Ecuador 00 01 2019 00 01 2019 44 2 43 50

2007 15(2) 199-208 2006 First 2002 2011 29(1) 59-69 2003 2005 MAG 2019 2010 2015 13(1) 28-40 2017 1999 2015 68(4) 635-45 2002 Chinese