@article {9585,
	title = {Unusual vortex structure in ultrathin Pb (Zr0.5 Ti0.5) O3 films},
	journal = {Journal of Applied Physics},
	year = {2007},
	doi = {10.1063/1.2404534},
	author = {Zhongqing Wu and Ningdong Huang and Zhirong Liu and Jian Wu and Wenhui Duan and Bing-Lin Gu}
}
