BibTex format
@article{Portela:2015:10.1136/postgradmed-2014-003620rep,
author = {Portela, MC and Pronovost, PJ and Woodcock, T and Carter, P and Dixon-Woods, M},
doi = {10.1136/postgradmed-2014-003620rep},
journal = {POSTGRADUATE MEDICAL JOURNAL},
pages = {343--354},
title = {How to study improvement interventions: a brief overview of possible study types},
url = {http://dx.doi.org/10.1136/postgradmed-2014-003620rep},
volume = {91},
year = {2015}
}