0034-7744 0034-7744 S0034-77442018000200495 10.15517/rbt.v66i2.33377 Brazil Brazil Brazil Brazil 00 06 2018 00 06 2018 66 2 495 502

2014 86 373-82 2011 74 822-8 2015 35 259-72 2015 2015 120 174-83 1993 2 331-45 2009 60 2897-905 2009 682 71-81 1997 45 3152-7 2009 2016 227 1-10 2014 763 30-55 2015 63 8981-90 R Development Core Team 2011 2013 68 433-8 2017 178 359-67 2007 378 63-6