TY  - JOUR 
T1  - Explaining variability
JO  - Dental Press Journal of Orthodontics
A1  - Normando, David
SN  - 2176-9451
UL  - 10.1590/2177-6709.21.6.015-016.edt
VL  - 21 
Y1  - 2016
PB  - Brasil 
ER  -