Article 30 [Prohibition of New Customs Duties or Charges Having Equivalent Effect]Kerikmäe, Tanel; Särav, SandraTreaty on the Functioning of the European Union - A Commentary2021 / p. 711-718 https://doi.org/10.1007/978-3-030-43511-0_31 Article 33 [Customs Cooperation]Kerikmäe, Tanel; Särav, Sandra; Hamulak, OndrejTreaty on the Functioning of the European Union - A Commentary2021 / p. 733-736 https://doi.org/10.1007/978-3-030-43511-0_34