@article {10587,
	title = {Photoreflectance study of AlAs/GaAs gradient period superlattice},
	journal = {Applied Physics Letters},
	year = {1992},
	pages = {2193-2195},
	doi = {10.1063/1.108292},
	author = {Hongwei Xu and Xiaochuan Zhou and Guichang Xu and Quangang Du and Enge Wang and Dingsheng Wang and Lingjun Zhang and Chenjia Chen}
}
