Co-operative Trial in Analytical Chemistry
Seven specimens were sent to 6 laboratories in 3 separate batches and each analysed for Analyte. Each analysis was duplicated.
Analytical Methods Committee (1987) Recommendations for the conduct and interpretation of co-operative trials, The Analyst 112, 679--686.
Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth edition. Springer.