BibTex format
@article{Gold:2012:10.1111/j.1600-0447.2012.01922.x,
author = {Gold, C and Erkkila, J and Crawford, MJ},
doi = {10.1111/j.1600-0447.2012.01922.x},
journal = {ACTA PSYCHIATRICA SCANDINAVICA},
pages = {307--314},
title = {Shifting effects in randomised controlled trials of complex interventions: a new kind of performance bias?},
url = {http://dx.doi.org/10.1111/j.1600-0447.2012.01922.x},
volume = {126},
year = {2012}
}