References
- SCHWENTEK , H. 1971 . The sunspot cycle 1958/70 in ionospheric absorption and stratospheric temperature . J. atmos. terrestr. Phys. , 33 : 1839 – 1852 .
- SHAPIRO , R. and WARD , F. 1962 . J. atmos. Sci. , 19 : 506
- Max‐Planck‐Institut für Aeronomie D3411 Katlenburg‐Lindau 3, Germany.