Ting Hu Ran Mo Pu Xiong Zengyang Li Qiong Feng Formal Definition and Automatic Generation of Semantic Metrics: An Empirical Study on Bug Prediction. 92-102 2021 SCAM https://doi.org/10.1109/SCAM52516.2021.00020 conf/scam/2021 db/conf/scam/scam2021.html#HuMXLF21