BibTex format
@article{Penn:1993:10.1109/77.233348,
author = {Penn, SJ and Alford, NM and Button, TW and Court, GR},
doi = {10.1109/77.233348},
journal = {IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY},
pages = {1157--1160},
title = {THE MAGNETIC HYSTERESIS OF POLYCRYSTALLINE YBa<sub>2</sub>Cu<sub>3</sub>O<sub>x</sub>},
url = {http://dx.doi.org/10.1109/77.233348},
volume = {3},
year = {1993}
}