Chen X, Li Y, Xiong K, Aizicovici S, Xie Y, Zhu Q, et al. (March 1998). "Cancer gene therapy by direct tumor injections of a nonviral T7 vector encoding a thymidine kinase gene". Human Gene Therapy9 (5): 729–36. PMID9551620. doi:10.1089/hum.1998.9.5-729.
Chen X, Li Y, Xiong K, Aizicovici S, Xie Y, Zhu Q, et al. (March 1998). "Cancer gene therapy by direct tumor injections of a nonviral T7 vector encoding a thymidine kinase gene". Human Gene Therapy9 (5): 729–36. PMID9551620. doi:10.1089/hum.1998.9.5-729.