Systematic techniques for assisting recruitment to trials (START): study protocol for embedded, randomized controlled trials

Jo Rick, Jonathan Graffy, Peter Knapp, Nicola Small, David J Collier, Sandra Eldridge, Anne Kennedy, Chris Salisbury, Shaun Treweek, David Torgerson, Paul Wallace, Vichithranie Madurasinghe, Adwoa Hughes-Morley, Peter Bower