1. C. C. Swisher III and G. H. Curtis, Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, CA 94709 USA.
2. W. J. Rink and H. P. Schwarcz, Department of Geology, McMaster University, Hamilton, Ontario, Canada L8S 4M1.
3. S. C. Antón, Department of Anthropology, University of Florida, Gainesville, FL 32611, USA.
4. A. Suprijo and Widiasmoro, Laboratory of Bioanthropology and Paleoanthropology, Gadjah Mada University, Yogyakarta, Indonesia, 55281.