Milk - Determination of nitrogen content - Part 3: Block-digestion method (Semi-micro rapid routine method) (ISO 8968-3:2004); German version EN ISO 8968-3:2007— 16 стр.
Accuracy (trueness and precision) of measurement methods and results - Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method (ISO 5725-2:1994 including Technical Corrigendum 1:2002)— 97 стр.