@article{Palmer2008,
author = {Palmer, T.M. and Peters, J.L. and Sutton, A.J. and Moreno, S.G.},
title= {Contour-enhanced funnel plots for meta-analysis},
year = {2008},
doi = {10.1177/1536867X0800800206},
volume = {8},
number = {2},
pages = {242--254},
}