Effect of a behaviour-change intervention on handwashing with soap in India (SuperAmma): a cluster-randomised trial oleh Dr. Adam Biran, PhD, Wolf-Peter Schmidt, PhD, Kiruba Sankar Varadharajan, MSc, Divya Rajaraman, PhD, Raja Kumar, MSc, Katie Greenland, MSc, Balaji Gopalan, BTech, Robert Aunger, PhD, Val Curtis, PhD