1. Gräsbeck R (1972) Scand J Clin Lab Invest 29:Suppl 126:19.2
2. Lange HF (1946) Acta Med Scand Suppl 176:109, 111
3. Whitehead TP (1972) Scand J Clin Lab Invest 29:Suppl 126:19.4
4. Büttner H (1972) Scand J Clin Lab Invest 29:Suppl 126:19.5
5. Egger E (1972) Scand J Clin Lab Invest 29:Suppl 126:19.6