1. D. Masera and A. Faaij, “Renewable Energy for Inclusive and Sustainable Industrial Development. The Case of Biomass Gasification.,” p. 41, 2014.
2. Associação Bandeira Azul da Europa, “Montado,” 2015. https://desafiouhu.abae.pt/ecossistemas-de-portugal/montado/
3. M. Sottomayor, “Potencial Económico da Bolota em Portugal: Análise Exploratória.” pp. 1–14, 2015.
4. A. Yuksel, “What is a Dual Fuel Engine, and its Benefits for Oil and Gas Applications?,” 2021. https://www.cummins.com/news/2021/09/29/what-dual-fuel-engine-and-its-benefits-oil-and-gas-applications
5. H. Guo, W. S. Neill, and B. Liko, “The Combustion and Emissions Performance of a Syngas-Diesel Dual Fuel Compression Ignition Engine,” in ASME 2016 Internal Combustion Engine Division Fall Technical Conference, Oct. 2016. doi: https://doi.org/10.1115/ICEF2016-9367.