Basim A. Al-Qayim, S. O. Abdullah, and Sherwood W. Wise Jr. “Biostratigraphic Analysis of the K/Pg Boundary Using Calcareous Nannofossil from Sulaimani Area, Kurdistan Region, Iraq”. Kuwait Journal of Science, vol. 47, no. 4, Oct. 2020, https://journals.ku.edu.kw/kjs/index.php/KJS/article/view/7388.