Caliendo AM, Valsamakis A, Bremer JW, Ferreira-Gonzalez A, Granger S, Sabatini L, Tsongalis GJ, Wang YF, Yen-Lieberman B, Young S, Lurain NS. Multilaboratory evaluation of real-time PCR tests for hepatitis B virus DNA quantification. J Clin Microbiol. 2011 Aug; 49(8):2854-8.