Chenarani, Atefeh, Shafiee Ardestani, Meysam, Vahidinia, Mohammad (2022). Biocorrelation, Biostratigraphy and determination basal of the Aptian stage at Tirgan Formation , west of Kopeh-Dagh sedimentary basin, NE Iran. *Iranian Journal of Petroleum Geology*, 11(21), 78-97. 10.52547/ispg.33928.11.21.78