[
Barro, R.J., & Sala-i-Martin, X. (1992). Convergence. Journal of Political Economy, 100(2), 223–251. http://nrs.harvard.edu/urn-3:HUL.InstRepos:3451299
]Search in Google Scholar
[
Brock, W.A., Scheinkman, J.A., Dechert, W.D., & LeBaron, B. (1996). A Test for Independence Based on the Correlation Dimension. Econometric Reviews, 15(3), 197–235. https://doi.org/10.1080/07474939608800353
]Search in Google Scholar
[
Communication from the Commission to the European Parliament, the Council, the European Economic and Social Committee and the Committee of the Regions Empty. Forging a Climate-Resilient Europe – the New EU Strategy on Adaptation to Climate Change. COM(2021) 82 final. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=COM%3A2021%3A82%3AFIN
]Search in Google Scholar
[
Cordell, D. (2010). The Story of Phosphorus: Sustainability Implications of Global Phosphorus Scarcity for Food Security. [Doctoral thesis, Linköping University]. Linköping Studies in Arts and Science, 509. Linköping University Electronic Press. https://liu.diva-portal.org/smash/get/diva2:291760/FULLTEXT01.pdf
]Search in Google Scholar
[
Davis, R.D. (2006). The Perception of Biosolids Use in Agriculture: Summary of Survey Findings. WRc Report UC7181/to Water UK.
]Search in Google Scholar
[
Dyrektywa Rady z dnia 12 czerwca 1986 r. w sprawie ochrony środowiska, w szczególności gleby, w przypadku wykorzystywania osadów ściekowych w rolnictwie (Dz.U. L 181). https://eur-lex.europa.eu/legal-content/PL/TXT/?uri=CELEX:31986L0278
]Search in Google Scholar
[
EurEau. (2021). Waste Water Treatment – Sludge Management. Briefing Note. https://www.eureau.org/resources/briefing--notes/5629-briefing-note-on-sludge-management/file
]Search in Google Scholar
[
European Commission. (2010). Environmental, Economic and Social Impacts of the Use of Sewage Sludge on land. Final Report. Part II: Report on Options and Impacts. Risk & Policy Analysis (RPA), Milieu, WRc (DG ENV.G.4/ETU/2008/0076r). https://op.europa.eu/it/publication-detail/-/publication/c969374b-01a5-11ec-8f47-01aa75ed71a1/language-en/format-PDF
]Search in Google Scholar
[
Eurostat. (2023). Sewage Sludge Production and Disposal. https://ec.europa.eu/eurostat/databrowser/product/page/env_ww_spd
]Search in Google Scholar
[
Food and Agriculture Organization of the United Nations (FAO). (2010). The Wealth of Waste. The Economics of Wastewater Use in Agriculture. FAO Water Reports, 35. https://www.fao.org/policy-support/tools-and-publications/resources-details/en/c/1508052/
]Search in Google Scholar
[
Gude, V.G. (2015). Energy and Water Autarky of Wastewater Treatment and Power Generation Systems. Renewable Sustainable Energy Reviews, 45, 52–68. https://doi.org/10.1016/j.rser.2015.01.055
]Search in Google Scholar
[
Hudcová, H., Vymazal, J., & Rozkošný, M. (2019). Present Restrictions of Sewage Sludge Application in Agriculture within the European Union. Soil and Water Research, 14(2), 104–120. https://doi.org/10.17221/36/2018-SWR
]Search in Google Scholar
[
Ivanov, B. (2020). Konvergirane na Balgarkoto zemedelie v selskoto stopanstvo na EC. Science, ХХХ, 5, 10–15. http://spisanie-nauka.bg/arhiv/5-2020.pdf
]Search in Google Scholar
[
Ivanov, B., & Bachev, H. (2021). Convergence Analysis of Waste Water Practices among EU Countries. Bulgarian Journal of Agricultural Science, 27(2), 289–296. https://www.researchgate.net/publication/351478274
]Search in Google Scholar
[
Ivanov, B., Marinova, S., Bachev, H., & Georgieva, V. (2021). Economic and Ecological Effects from Wastewater Use in Agriculture. https://www.researchgate.net/publication/349519553
]Search in Google Scholar
[
Ivanov, B. (2023). ). Rolya i znachenie na trasaction razhodi za upotrebata na utaikite v zemedelieto. In: Ivanov, B., Bashev, H., Marinova-Garvanska, S., Banov, M., Georgieva, V., Georgieva, R., Tsvyatkova, D., Tachev, Y., Stoychev, W., Paunova, G., & Stankova, D. Aspekti pri upotrebata na utaiki ot otpadachni vodi v zemedelieto (pp. 121–142). Institute of Agricultural Economics. https://www.researchgate.net/publication/375990045
]Search in Google Scholar
[
Jaramillo, M.F., & Restrepo, I. (2017). Wastewater Reuse in Agriculture: A Review about Its Limitations and Benefits. Sustainability, 9(10), 1734. https://doi.org/10.3390/su9101734
]Search in Google Scholar
[
Jiménez, B., Mara, D., Carr, R., & Brissaud, F. (2010). Wastewater Treament for Pathogen Removal and Nutrient Cconservation: Suitable Systems for Use in Developing Countries. In: A. Bahri, P. Drechsel, L. Raschid-Sally & M. Redwood (Eds.), Wastewater Irrigation and Health: Assessing and Mitigating Risk in Low-Income Countries (pp. 149–169). Routledge. https://publications.iwmi.org/pdf/H042608.pdf
]Search in Google Scholar
[
Kusz, D.A. (2019). The Local Instituttions and Transaction Costs of Public Aid in the Process of Agricultural Modernization. Zagadnienia Ekonomiki Rolnej / Problems of Agricultural Economics, 359(2), 43–68. https://doi.org/10.30858/zer/109922
]Search in Google Scholar
[
Maaß, O. (2019) Analyzing Transactions in Linked Value Chains of Wastewater Treatment and Crop Production. [Doctoral dissertation, Humboldt University of Berlin]. https://edoc.hu-berlin.de/handle/18452/20917.
]Search in Google Scholar
[
Mankiw, N.G., Romer, D., & Weil, D.N. (1992). A Contribution to the Empirics of Economic Growth. Quarterly Journal of Economics, 107(2), 407–437. https://doi.org/10.2307/2118477
]Search in Google Scholar
[
Marin, E., & Rusănescu, C.O. (2023). Agricultural Use of Urban Sewage Sludge from the Wastewater Station in the Municipality of Alexandria in Romania. Water, 15(3), 458. https://doi.org/10.3390/w15030458
]Search in Google Scholar
[
Marinova, S. (2001). Content of Organic Pollutants in Sludge from WWTP. Bulgarian Journal of Soil Science, Agro-chemistry and Ecology, 35, (1–3), 74–75.
]Search in Google Scholar
[
Przydatek, G., & Wota, A.K. (2020). Analysis on the Comprehensive Management of Sewage Sludge in Poland. Journal of Material Cycles and Waste Management, 22, 80–88. https://doi.org/10.1007/s10163-019-00937-y
]Search in Google Scholar
[
Report from the Commission to the European Parliament, the Council, the European Economic and Social Committee and the Committee of the Regions. Ninth Report on the Implementation Status and the Programmes for Implementation (as required by Article 17) of Council Directive 91/271/EEC Concerning Urban Waste Water Treatment. SWD(2017) 445 final. https://eur-lex.europa.eu/legal-content/en/TXT/?uri=CELEX:52017DC0749
]Search in Google Scholar
[
Romanian Insider (2020, June 26). Only 54% of Romania’s population had access to sewage systems in 2019. https://www.romania-insider.com/romania-population-sewage-2019
]Search in Google Scholar
[
Sala-i-Martin, X.X. (1994). Regional Cohesion: Evidence and Theories of Regional Growth and Convergence. CEPR Discussion Paper, 1075. Centre for Economic Policy Research (CEPR).
]Search in Google Scholar
[
Sarov, A., & Tsvyatkova, D. (2021). Opolzotvoryavane na utaikite ot prechistvatelny stanzii za otpadni vodi v zemeelieto kato agroecosystem usluga. In: H. Bachev (Eds.), Mechanism i formi na upravlenie na agrosystem uslugi v Bulgaria. (pp. 95–105). Institute of Agricultural Economics.
]Search in Google Scholar
[
Sulewski, P., & Gołaś, M. (2019). Environmental Awareness of Farmers and Farms’ Characteristics. Zagadnienia Ekonomiki Rolnej / Problems of Agricultural Economics, 361(4), 55–81. https://doi.org/10.30858/zer/115186
]Search in Google Scholar
[
Williamson, O.E. (1979). Transaction-Cost Economics: The Governance of Contractual Relations. The Journal of Law and Economics, 22(2), 233–261.
]Search in Google Scholar