BibTex format
@article{Isham:1998:10.1023/A:1026680806775,
author = {Isham, CJ and Butterfield, J},
doi = {10.1023/A:1026680806775},
journal = {INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS},
pages = {2669--2733},
title = {Topos perspective on the Kochen-Specker theorem: I. Quantum states as generalized valuations},
url = {http://dx.doi.org/10.1023/A:1026680806775},
volume = {37},
year = {1998}
}