BÖLLINGER, A. Energiespar-Contracting in der Landesbibliothek. WLBforum, Stuttgart, v. 8, n. 2/3, p. 32–35, 2006. DOI: 10.53458/wlbf.v8i2/3.428. Disponível em: https://journals.wlb-stuttgart.de/ojs/index.php/wlbf/article/view/428. Acesso em: 22 mai. 2022.