1. P.M. Gy, Sampling for Analytical Purposes, 1st Edition, John Wiley & Sons, Chichester, West Sussex, UK, 1998.
2. F.F. Pitard, Pierre Gy’s Sampling Theory and Sampling Practice: Heterogeneity, Sampling Correctness, and Statistical Process Control, 2nd Edition, CRC Press, Boca Raton, FL, USA, 1993.
3. Sampling Grain Shipments To Detect Genetically Modified Seed