KRATHWOHL, E. J. . Gas Purchasing-Business, Legal, and Contracting Issues. Distributed Generation & Alternative Energy Journal, [S. l.], v. 13, n. 2, p. 40–46, 1998. DOI: 10.13052/dgaej2156-3306.1325. Disponível em: https://journals.riverpublishers.com/index.php/DGAEJ/article/view/14781. Acesso em: 15 may. 2026.