Biogas Production from Microalgal Biomass Produced in the Tertiary Treatment of Urban Wastewater: Assessment of Seasonal Variations oleh Raúl Barros, Sara Raposo, Etiele G. Morais, Brígida Rodrigues, Valdemira Afonso, Pedro Gonçalves, José Marques, Paulo Ricardo Cerqueira, João Varela, Margarida Ribau Teixeira, Luísa Barreira