Gröber, K., Crosweller, D., Schröder, E., Kappauf, L., Surridge, T., Panchal-Segtnan, A., y Zurbrugg, C., «Sanitation as a business». Sustainable Sanitation Alliance, SuSanA, S.l., p. 8 p.; 4 fig.; 2 boxes, 2012.