TY  - JOUR 
T1  - Internal and external validity: can you apply research study results to your patients?
JO  - Jornal Brasileiro de Pneumologia
A1  - Patino, Cecilia Maria
A1  - Ferreira, Juliana Carvalho
SN  - 1806-3713
UL  - 10.1590/S1806-37562018000000164
VL  - 44 
Y1  - 2018
PB  - Brasil 
ER  -