1. Andrei, J. V., Dusmanescu, D., & Mieila, M. (2015). The influences of the cultural models on agricultural production structures in Romania and some EU-28 countries-a perspective. Economics of Agriculture, 62(297-2016-3679), 293-307;
2. Agri-food data portal, and European agriculture and common agricultural policy, https://agridata.ec.europa.eu/extensions/DashboardCereals/CerealsTrade.html, (accessed 12 June 2021);
3. Aznar-Sánchez, J. A., Piquer-Rodríguez, M., Velasco-Muñoz, J. F., & Manzano-Agugliaro, F. (2019). Worldwide research trends on sustainable land use in agriculture. Land Use Policy, 87, 104069;
4. Brussels, 8.7.2013 COM (2013) 517. (accessed 12 June 2021) Advisory Communication on the sustainable use of phosphorus, https://ec.europa.eu/environment/consultations/pdf/phosphorus/EN.pdf;
5. Constantin Anghelache, et al, (2019) Econometrie, Ed.Artifex, pp.35-78, ISBN 978-973-7631-51-0. Bucharest, Romania;