My thesis concerns the principle of mutual recognition in EU law.

EU law, EEA law, human rights law, constitutional law, international law and contracts law. 

• Tollef Otterdal Heggen, Er nasjonale tilsynsmyndigheiter for finansmarknaden eigentleg nasjonale? Krav om uavhengige nasjonale tilsynsmyndigheiter for finansmarknaden i EU, EØS og Noreg (Karnov Forlag 2024)
• Tollef Otterdal Heggen and Matias Tvermyr Holmen, "No principle of State liability for breaches of EEA law attributable to the judiciary? Some reflections on the seventh round of the Dartride saga" (2024) EFTA-studies.org
• Tollef Otterdal Heggen, "Forslaget til ny finanstilsynslov overheld ikkje gjeldande EØS-rettslege uavhengigheitskrav" (2024) Rett24
• Tollef Otterdal Heggen, "EEA state aid rules as salvation for a municipality that forgot to get paid" (2024) EFTA-studies.org
• Halvard Haukeland Fredriksen and Tollef Otterdal Heggen, "The ECJ’s ruling on the Mobility Package and the EEA: Is the obligation requiring vehicles to return every eight weeks to the operational centre of the transport undertaking still good EEA law?" (2024) EFTA-studies.org
• Tollef Otterdal Heggen, Stjernenote til EØS-arbeidstakarlova, Lovkommentarar Karnov (2024)
• Halvard Haukeland Fredriksen and Tollef Otterdal Heggen, "EFTA-domstolen som prejudikatdomstol" (2025) Rett24