FRANK, Wilhelm. Energieperspektiven: Primary Energy. Present Status and Future Perspectives VIII. Wirtschaft und Gesellschaft, Wien, Österreich, v. 9, n. 2, p. 302–306, 1983. Disponível em: https://journals.akwien.at/index.php/wug/article/view/2411.. Acesso em: 23 mar. 2026.