Pemetrexed with gefitinib or pemetrexed alone in advanced non-small cell lung cancer with acquired resistance to EGFR tyrosine kinase inhibitors
LIU Hongliu, YANG Jiamei
China Oncology . 2017, (2): 135 -139 .  DOI: 10.19401/j.cnki.1007-3639.2017.02.009