Plasma levels of free metanephrines and 3-methoxytyramine indicate a higher number of biochemically active HNPGL than 24- h urinary excretion rates of catecholamines and metabolites - van Duinen, N; Corssmit, E P; de Jong, W H (Eur J Endocrinol, 2013)
doi:10.1530/EJE-13-0529