BibTex format
@inbook{Butterfield:2001,
author = {Butterfield, J and Isham, C},
booktitle = {Physics meets philosophy at the Planck scale: contemporary theories in quantum gravity},
editor = {Callender and Huggett},
pages = {33--89},
publisher = {Cambridge University Press},
title = {Spacetime and the philosophical challenge of quantum gravity},
year = {2001}
}