Roberts L; Smith W; Jorm LR; Patel M; Douglas RM; McGilchrist C, 2000, 'Effect of Infection Control Measures on the Frequency of Upper Respiratory Infection in Child Care: A Randomized, Controlled Trial', Pediatrics, vol. 105, pp. 738 - 742, http://pediatrics.aappublications.org/content/105/4/738.long