JOURNAL OF APPLIED PHYSICS, vol. 91, no. 11, page. 9072 - 9077, 2002-06-01
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, vol. 83, no. 5, page. 1284 - 1286, 2000-05
PLOS ONE, vol. 10, no. 3, 2015-03-24
, 2015-03
PLoS ONE, vol. 11, no. 4, 2016-04-13