src/HOL/Hoare/document/root.bib

proper syntax;

@inproceedings{MehtaN-CADE03,author={Farhad Mehta and Tobias Nipkow},
title={Proving Pointer Programs in Higher-Order Logic},
booktitle="Automated Deduction --- CADE-19",editor="F. Baader",
year=2003,publisher="Springer",series="LNCS",volume={2741},pages={121--135}}

@article{MehtaN-IC05,author={Farhad Mehta and Tobias Nipkow},
title={Proving Pointer Programs in Higher-Order Logic},
journal="Information and Computation",year=2005,volume=199,pages={200-227}}