PredeÈ›eanu-Dragne, Daniela, Dan Popescu, and Valentina Nicolae. “Volunteering – An Efficient Collaborative Practice for the Local Communities Sustainability. Empirical Study”. European Journal of Sustainable Development 8, no. 5 (October 1, 2019): 302. Accessed December 21, 2024. http://ecsdev.org/ojs/index.php/ejsd/article/view/943.