LANGTON, M. J. . Engineered Savings Programs (ESP) An Alternative to Performance Contracting . Strategic Planning for Energy and the Environment, [S. l.], v. 21, n. 1, p. 27–35, 2023. Disponível em: https://journals.riverpublishers.com/index.php/SPEE/article/view/20411. Acesso em: 18 jun. 2026.