1. AHSAN , A. 1993 Petroleum Biodegradation in the Tertiary Reservoirs of the North Sea, Cand. Scient Thesis in Geology Department of Geology University of Oslo 173
2. AHSAN , S.A. 1998 The application of concepts in Petroleum Geochemistry to Field exploration, development, production and post-production stages Ph.D. thesis in Geology University of Oslo
3. Petroleum biodegradation in the Tertiary reservoirs of the North Sea;AHSAN;Marine and Petroleum Geology,1997
4. Inter and intrafield hydrocarbon compositional variation in the Ula and the Gyda Fields (Central Graben-North Sea)-Implications for understanding the controls on hydrocarbon distribution within and between these fields;AHSAN;Organic Geochemistry,1998
5. Geochemical correlation of Windalia oil extracts of Winning Group (Cretaceous) potential source rocks, Barrow Subbasin, Western Australia;ALEXANDER;AAPG Bull.,1981