Hung*, N. H., Minh, N. T., Hung, D. D., & Hung, N. B. (2017). New discovery of late early ordovician graptolites and discussion on stratigraphic sequence of paleozoic sediments in the Dinh Ca - Trang Xa Section, Vo Nhai Disctrict, Thai Nguyen Province, Northeast Vietnam. Vietnam Journal of Earth Sciences, 39(1), 76–86. https://doi.org/10.15625/0866-7187/39/1/9229