Expression of hypoxia inducible factor-1 alpha in human lumbar nucleus pulposus of different herniated types 
Liu Xing-zhen, Fu Zhi-yi, Shen Kang-ping, Jin Wen-jie, Wu Yu-jie
Chinese Journal of Tissue Engineering Research . 2015, (29): 4700 -4709 .  DOI: 10.3969/j.issn.2095-4344.2015.29.021