1. Pioneer Hi-Bred International, Inc.; 7431 Kaumualii Highway, P.O. Box 596 Kekaha HI 96752
2. CIMMYT; Apdo. Postal 6-641 06600 Mexico D.F. Mexico
3. CSIRO Tropical Agriculture; 306 Carmody Rd. St. Lucia QLD 4067 Australia
4. IRRI; P.O. Box 933 Manila Philippines