Jiangying Liao Liao, J. Y., Lou, I. C., & De Los Reyes, F. L. (2004). Relationship of species-specific filament levels to filamentous bulking in activated sludge. Applied and Environmental Microbiology, 70(4), 2420–2428. https://doi.org/10.1028/AEM.70.4.2420-2428.2004