BibTex format
@article{Terwee:2011:10.1016/j.joca.2011.01.002,
author = {Terwee, CB and Bouwmeester, W and van, Elsland SL and de, Vet HCW and Dekker, J},
doi = {10.1016/j.joca.2011.01.002},
journal = {OSTEOARTHRITIS AND CARTILAGE},
pages = {620--633},
title = {Instruments to assess physical activity in patients with osteoarthritis of the hip or knee: a systematic review of measurement properties},
url = {http://dx.doi.org/10.1016/j.joca.2011.01.002},
volume = {19},
year = {2011}
}