Combination of analytical quality specifications based on biological within- and between-subject variation124, Petersen, P.H., Fraser C.G., Jorgensen L., Brandslund I., Stahl M., Gowans E., Libeer J.C., and Ricos C. , Ann.Clin.Biochem., 0/11/2002, Volume 39, Issue Pt 6, Number 550, p.543 - 550, (2002)