Collecting and analysing cost data for complex public health trials: reflections on practice oleh Neha Batura, Anni-Maria Pulkki-Brännström, Priya Agrawal, Archana Bagra, Hassan Haghparast- Bidgoli, Fiammetta Bozzani, Tim Colbourn, Giulia Greco, Tanvir Hossain, Rajesh Sinha, Bidur Thapa, Jolene Skordis-Worrall