Continental lacustrine fine-grained lithofacies, assemblage and geological significance of unconventional petroleum: A case study of the Paleogene of the 4th member of the Shahejie... oleh Ying Li, Zeng-Xue Li, Dong-Dong Wang, Guang-Zeng Song, Da-Wei Lv, Lusheng-Yin, Hai-Yan Liu, Chun-Hua Xu, Fan-Fei Kong, Qiao-Yu Han