Edwards, P., Cooper, R., Roberts, I., & Frost, C. (2005). Meta-analysis of randomised trials of monetary incentives and response to mailed questionnaires. BMJ Group.
Παραπομπή Chicago StyleEdwards, P., R. Cooper, I. Roberts, και C. Frost. Meta-analysis of Randomised Trials of Monetary Incentives and Response to Mailed Questionnaires. BMJ Group, 2005.
Παραπομπή MLAEdwards, P., R. Cooper, I. Roberts, και C. Frost. Meta-analysis of Randomised Trials of Monetary Incentives and Response to Mailed Questionnaires. BMJ Group, 2005.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.