Effect of a youth-led early childhood care and education programme on children's development and learning in rural Sindh, Pakistan (LEAPS): a stepped-wedge cluster-randomised implementation trial. - Yousafzai AK; Siyal S; Franchett EE; Dai Q; Rehmani K; Sudfeld CR; Bhamani S; Hakro S; Reyes CR; Fink G; Ponguta LA (The Lancet. Child & adolescent health, 2025)