KUANG, Rong-Guang, et al. “Expression and Significance of IGF-2, PCNA, MMP-7, and α-Actin in Gastric Carcinoma With Lauren Classification”. Turkish Journal of Gastroenterology, vol. 24, no. 2, Jan. 2013, pp. 99-108, doi:10.4318/tjg.2013.0571.