1. Smith-Rose, R. L., ICSU Rev., 3, 61 (1961).
2. “Final Acts of the Extraordinary Administrative Radio Conference to allocate Frequency Bands for Space Radio Communication Purposes”, I.T.U., Geneva (1963).
3. Weinreb, S., Barrett, A. H., Meeks, M. L., and Henry, J. C., Nature, 200, 829 (1963).