1. Gallard R, Gearing A, The cytokine. London: Academic Press; 1994:265.
2. Whicher J, Banks R. Cytokines as tumour markers. Scand J Clin Lab Invest 1995;55 [Suppl]: 122.
3. Nicola N: An introduction to the cytokines. In: Nicola N, ed. Guidebook to cytokines and their receptors, Oxford: Oxford University Press 1994;1–7.
4. Gräsbeck R. Terminology and biological aspects of reference values. In: Benson E, Rubin M, eds Logic and economics of clinical laboratory use, New York: Elsevier: 1978;77–90.
5. Solberg HE, Gräsbeck R. Reference, values. Adv Clin Chem 1989;27:1.