Efficacy and safety of gemcitabine plus raltitrexed or S-1 versus standard third-line therapies in metastatic colorectal cancer: a retrospective cohort study - Tao, Jialong; Zhang, Yingtian; Wang, Yanjie; Huang, Sijia; Gao, Wenwen; Dai, Liya; Feng, Zhengyang; Jiao, Chenchen; Zhang, Yusong (Journal of Gastrointestinal Oncology; Vol 15, No 2 (April 30, 2024): Journal of Gastrointestinal Oncology, 2024)