?url_ver=Z39.88-2004&rft_id=10.1016%2Fj.coal.2017.06.010&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.aulast=Ayinla&rft.au=Ayinla%2C+H.A.&rft.aufirst=H.A.&rft.volume=180&rft.issn=01665162&rft.atitle=Petrographic+and+geochemical+characterization+of+the+Upper+Cretaceous+coal+and+mudstones+of+Gombe+Formation%2C+Gongola+sub-basin%2C+northern+Benue+trough+Nigeria%3A+Implication+for+organic+matter+preservation%2C+paleodepositional+environment+and+tectonic+settings&rft.pages=67-82&rft.title=International+Journal+of+Coal+Geology&rft.date=2017&rft.genre=article