RT Journal Article
SR Electronic
T1 External validity is also an ethical consideration in cluster-randomised trials of policy changes: the author’s reply
JF BMJ Quality & Safety
JO BMJ Qual Saf
FD BMJ Publishing Group Ltd
SP 168
OP 168
DO 10.1136/bmjqs-2018-008805
VO 28
IS 2
A1 Hemming, Karla
A1 
YR 2019
UL http://qualitysafety.bmj.com/content/28/2/168.abstract
AB