Кунєв, Ю. Д., and Ю. І. Пивовар. “CUSTOMS SYSTEM: METHODOLOGICAL FUNDAMENTALS FOR DEFINITION OF THE CONCEPT”. Scientific Works of National Aviation University. Series: Law Journal "Air and Space Law", vol. 4, no. 53, Nov. 2019, pp. 76-84, doi:10.18372/2307-9061.53.14294.