1. Biometrics and Statistics Unit, Crop Research Informatics Laboratory (CRIL); International Maize and Wheat Improvement Center (CIMMYT); Apdo. Postal 6-641 Mexico D.F. Mexico
2. Department of Plant and Soil Sciences and Department of Statistics; University of Kentucky; Lexington KY 40546-03121
3. Alberta Agriculture and Food; #300, 700-113 Street Edmonton AB T6H 5T6 Canada
4. Department of Agricultural, Food and Nutritional Science; University of Alberta; Edmonton AB T6G 2P5 Canada