1. E. Fosdick and M. Hewitt, “Effect of the earth’s oblateness and atmosphere on a satellite orbit,” Report ER8262, The Martin Company.
2. The Harvard College Observatory card 1408 of June 24, 1958 gives a new value of f = (a−b)∕a as 1∕298.38±0.7.
3. Lecar, Sorenson, and Eckels, “A determination of the coefficientJof the second harmonic in the earth’s gravitational potential from the orbit of satellite 1958 beta 2,” J. Geophys. Research (to be published). Operating with somewhat better data than Dr. O’Keefe of Army Map Service they obtain a value of f = 1∕298.32±05.