Test-enhanced learning in the classroom: long-term improvements from quizzing
Journal of Experimental Psychology Applied (2011) - Comment
pubmed: 22082095  doi: 10.1037/a0026252  issn: 1939-2192  issn: 1076-898x 

Henry L. Roediger, Pooja K. Agarwal, Mark A. McDaniel, Kathleen B. McDermott